[Krazibo]

Get some flash cards, and just write the functional groups on them. When your not doing anything or waiting for something, randomly pick two flash cards and try to synthesize one from the other with the proper reagents. I haven't tried this with the actual cards, but I did it on paper. Check answers through book.

Write on cards, alkyne, alkene, alkane, ketone, carboxylate acid, alcohol, etc.