Getting beans easily
The best way to get Bertie Bott Beans is in the Dueling Club. After you beat the last duel challenger you get 400 beans. Go back and beat him as many times you want. You will keep getting more and more beans, and that will allow you to trade for the Nimbus 2001 and Quidditch armour from Fred and George. Fred and George are standing right outside the Quidditch gate.

Easy Bertie Blotts Every Flavor Beans:
When you exit of the Gryffindor Tower notice the object in the corner. Hit it with Flipendo and three Beans will appear. Go around the corner and walk at least three steps away. Return and cast Flipendo again to get three more Beans. Repeat this to get as many Beans as needed.

Use the Nimbus 2000 Broomstick and fly above Hogwarts. Fly through the rings to get free Beans. A blue ring gives 10 Beans, a yellow ring gives 1 Bean, a red ring gives 3 Beans and a green ring gives 2 Beans.

At the beginning at Ron's house is a tool chest in their barn. Every time it moves on its own means that you can shoot it with Flapendo to get more beans.

Nimbus 2000 Broomstick:
On the second day of school, go to the Quidditch practice. Complete the training with a "B" or better rank to get the Nimbus 2000 flying broomstick. You can now fly anywhere around the school during the day. Note: You can only land on grass and cannot fly inside the school.

Easy Wizard Cards:
Go to the Burrow and Diagon Alley. Look for chests there for Wizard Cards.

Go Neville's games, especially Broom Racing, to get Wizard Cards. Note: You will have to pay Beans to participate in Broom Racing and Gnome Tossing, Gnome Dunking is free.

In Ron's barn at the very beginning is a card on top of the rafters. To get it, you need to climb the chicken coop outside.

Easy points:
In the Chamber Of Secrets, destroy paintings on the wall. You will open the painting and get 100 points for Gryffindor.

After returning from the Whomping Willow, head deep to your right when Professor Snape finishes scolding you. There, in a corner, you will find your first Notice Board Item. You can return it to the Notice Board before or after you go to the Restroom Shop the Weasley's set up, earning you the very first 10 points in the game, and possibly a Wizards Card.

Easy Sickles:
Once you have collected your Standard Book of Spells (Grade 2) in Diagon Alley, you can cast Flipendo to break barrels and uncover Sickles that you can use to buy items such as Stink Pellets at Gambol and Japes.

Bertie Botts Bean Bag (100 Bean capacity):
Use the Skurge spell on a chest covered in ectoplasm behind a tapestry (you need the scissors spell) on the third floor, by the Defense against the Black Arts classroom.

Bertie Botts Bean Bag (200 Bean capacity):
Gather every item for the students around Hogwarts (not the Notice Board). You have to actually find the people. The final person will give you a key to the confiscated items room. In there are six Wizards cards and the biggest Bertie Bots Bean Bag.

Sneaking around at night:
When sneaking around at night, you need to get by many of the prefects. When you need to get by them, simply crawl under the bookcase to the left of the portrait that leads to the Griffondore common room. It leads through a secret passage that takes you to the fourth floor.

When sneaking around and you do not want to walk slowly, you can use various objects and spells to distract the prefects. Stink Pellets are not too reliable, but the non-explodable luminous balloons work well. As for spells, try Flapendo.

Avoiding ghosts:
When you do not want to be hit by ghosts and lose all your items (Balloons, Beans, and sometimes Stink Pellets) just stand on the ledge until the specter nears you. Tap the controller so that you will fall and catch the ledge. When you are hanging, they cannot hit you and cause your items to go flying.

Expelliarmus Challenge:
Use your spell that cuts down tapestries and ropes on the spiked ball. Walk up close to the edge and hold your trigger button, charge up for a half second and cast. Note: If you throw the imps into the fiery pits, they will die and you do not have to worry about them. Likewise, if you throw them all away you cannot put them into the cages to get out; but when all are indeed gone, they respawn from that hatch in the wall at the first ramp.

Professor Flitwick's Incedio Challenge:
Once you get the Incedio Spell, return to the main room and make sure the two pillars are down. Go into one of them and switch the flame direction so that the flames are both are on one side of the room. On the other side, use Incedio to light the pigs and Flapendo to point them up to lift the platform; then again on the other one. Run quickly to the switch by the exit. If successful the door, will be unlocked halfway. You will need to do likewise with the other side. Note: You do not have to charge at all -- this gives you a few extra needed seconds.

Fighting with Expelliarmus:
When in one of the few battles with Hogwart's students (just the Slytherin Gang, all others leave you alone), let them make the first shot and bounce it back. Just as you do, use your Flapendo with a quarter to half second charge to knock them back, thus trapping them with two spells to knock back, which they can never manage. Note: Beware, just as you finish casting Flapendo (depending on distance), you will be forced to use your Expelliarmus almost instantly.

Defeating the Giant Mother Spider:
To get to it, use your Lumos spell to light the floor and follow the trail of spiders. Unlike the book, the spiders that are not normal size will try to kill you. Attack them with Incendio. When fighting the Giant Mother Spider, do not try to hurt the spider itself. Instead, use your Incendio spell to burn the web it has attached to the various trees. When done, it will fall into the pit and you will slip in after it. In here, just run around until it rears its head and exposes its soft under-belly. It is the only part that is susceptible to second level magic. Note: It is best to not charge and use rapid firing to get a little extra damage.

Defeating the Giant Mother Spider 2:
While fighting it, you may notice little sacks being dropped and suspended by webbing. Shoot them down with Flapendo and collect health and Bean power ups from Hedwig.

Defeating the Giant Spider:
To defeat the Giant Spider in the Dark Forest, circle around him and cast Rictosempra. He will not shoot any spider webs at you.

Defeating the Whomping Willow:
When the Whomping Willow starts to pound into the ground, hide in the corner where you entered its lair. The shock wave cannot reach you in here, unless you stray too far from it. Should you get hit, you should have refilled your potion Vile before you entered. Also, Hedwig will drop Cauldron Cakes and Beans for your aid. Note: Rapid firing technique is recommended. Lock on to the limbs after they finish pounding and fire a quick shot, then wait to lock onto the Willow's Eye. Then, fire repeatedly until it stops hurting him before running back to your hiding hole.

Personal Requests and Notice Board:
The Notice Board in the Gryffondor common room usually gives a location, but higher up as you near completion they start to give vague clues, such as "Could be anywhere on grounds". With personal requests, they do not ever really give you a clue, except the first one. However, the items are near the area in about a two acre search range.

Finding Lost Items
When in doubt, check Hagrid's Hut. Many of the lost items end up there.
3 Roots Needed
Search the left side of Hagrid's Hut, by the Herbology Center. From there, they all scatter (much like Neville's china set) behind Hagrid's Hut towards the Forbidden Forest. The person that wants these will give you the key to the Confiscated Items Room (six more cards and a bag to hold 200 Bertie Bott's Every Flavored Beans).
Lost Badge
Found on the Broom Flying Field, towards Hagrid's Hut and the Whomping Willow (still inside the Flying Court).
Lost Newspaper Article
Search the left side of Hagrid's Hut. Note: "Left" being if you were looking from his front door towards the castle (the side next to the Herbology Center).
Lost Wizards Hat
Found in a small patch of trees towards the Quiddich Court.
Neville's Crockery
Can be found close to the Flying Court and Hagrid's Hut. Up on a roof will be a multitude of his china set. Go about a fifteen to twenty five second flying trip from Neville (heading back).
Secretive Dragon Scale Gloves
The elusive gloves are by the lake, but not on land. They can be found just outside the Broom Flying lessons field, on the lakeside. You will notice a long strip is down low. On the far end are five torches (light with Incendio to get a Wizards Card), and in the middle somewhere should be the gloves.

Forbidden Forest spiders:
The spiders in the forest act as follows:

Tiny Black: Show you the path
Big Green: Jumpers (jump, run away, and jump again)
Big Red: Flingers (they spit)
Big White: Flingers (spit paralyzing venom)
Big Multicolor: Possible Jumper/Flinger mix.

Transformation spell:
After you acquire the spell and return to the main room, use it to get across the room on the other side of the gargoyle. You will need to use the hardly visible ledges to cross. Hang off the wall ledge to escape nearing ghosts, and push down the slabs to make a bridge. Once this is done, you will have to fight the gargoyle. It is recommended that you get on the right staircase, halfway up. Then, use the spell on the last stone and the door will open.