You need a large book, (Unless your handwriting is pretty small) The book's cover should be based on the type of magic you do, But Remember- Magic is always neutral. If you specialize in love spells, make the cover pink or red. If you do more career, fortune or money spells, make the cover green. If you do more White Magic aka,right hand magic, make the cover white or golden. If you do left hand magic AKA. dark magic, make the cover red or black.
Remember, the diary must have a lock or some sort of protection.You don't want it in the wrong hands do you?
Now in this very website, you can find a load of spells.Take them, create a few tiny diagrams related to them and you have just created your 3rd page.
How To Properly Write Spells:
Find out what color they are related to (view another one of my articles). Write the title with that color (only if you want.)
The first few pages should be related to Palmistry, Magic, Wicca,Etc.
And voila! You have just created your own book of shadows.