Ok there are few points I can help you with:
a) Theoretical: get a textbook, preferably with problems. I like disconection approach by Warren but there are more - you can google "advanced organic chemistry" and you will see
b) practical: Lab work, there is no way around it. I mean reading that for crystalization you need solvent in which is your compound highly solube at high temperatures and unsoluble at low temperatures is nice but finding that solvent to recrystalize your new compound could be rather difficult. So lab work it is, preferably doing as many different reactions as you can.