Higher Tier Skills Booklets
Not sure what you do know and what you don't know? Work through these skills booklets! Each one contains just a few examples of a bunch of different types of question. When you find a question you cannot do, find the name of the topic and check out the other resources for that topic ("Topic Booklets" and "Question Booklets").
(Psst... These booklets do not cover topics in depth and you should not make these the focus of your revision!)