As it is really hard to get them, I will post up a mini-walkthrough for this one part.
When you have to collect Fairy Wings as part of your homework assignment for Professor Snape you will get the chance to go to Hogsmeade (The Woods outside Hogwarts). When the fairies come out, use Hermione and cast the Flipendo spell and if you hit them then they will fall to the floor. You then have to use the Glacius spell and freeze the fairies, then walk over and pick them up.
To get rid of dementors aim and cast expecto patronem at the end to save sirius cast it then control your patronus to the dementor sucking sirius's soul (mainly the closest dementor to him)
To kill a Salamander first use the Glacius spell to put out the fire on its back and to turn it icy and then shoot it with Flipendo (Knockback Jinx).
On the fifth floor (Muggle Studies) there's a locked treasure chest in the room containing all the musical instruments. Directly opposite this is a gramophone, and you'll notice you can target it by holding down the R1 button. Have Hermione cast Reparo on the gramophone until you hear a bell-like sound, and the treasure chest will be unlocked. It contains a bunch of Every Flavour Beans.
There are four different ways to unlock 20 House Points. You will receive 20 of them each time you complete each of these tasks, equaling 80 in total after completing them all.
Collect all Vampire cards.
Collect all Goblin cards.
Collect all Giant cards.
Collect all Beast cards.
There are two different ways of getting extra endurance for Harry.
Collect all Quidditch cards
Collect all Wizard cards
There are two different ways to get extra endurance for Hermione. They are:
Collect all Hag cards
Collect all Witch cards
There are two ways to get extra endurance for Ron. They are:
Collect all Dragon cards
Collect all Classical Beast cards
If you cast Glacius on someone they'll turn blue!
This is a weird little glitch in the game, whilst doing the Carpe Retractum spellbook challenge, doors you open may remain open and if you go through them you end up in a pitch black place, however move forward as far as you can and you can end up in weird and wonderful places! In one I came out in the Glacius spellbook challenge, and in another in the room where malfoy locks neville up with a ghoul, an i enen found a room full of every flavour beans but the game made me walk through them so i couldn't collect them. It can be done with most of the doors in the c.r challenge, but afterwards you cannot get back again, so you might want to reset the game.
Get the complete set of cards as listed for the bonus:
20 House Points - All Beast Cards
Ron gets extra endurance - All Classical Beast Cards
Ron gets extra endurance - All Dragon Cards
20 House Points - All Giant Cards
20 House Points - All Goblin Cards
Hermione gets extra endurance - All Hag Cards
Harry gets extra endurance - All Quidditch Cards
20 House Points - All Vampire Cards
Hermione gets extra endurance - All Witch Cards
Harry gets extra endurance - All Wizard Cards