I hope what I WILL do will help enough.
I can't speak for the chemistry, caUSE i'M TAKING edexcel.
For Bio though, Idon't think it can be made enjoyable. What helps massively, or so I've been told, is going through tons of past papers. 2003 to 2009 is what I'm personaLLY DOING.
Use the markschemes to write down the answers to questions that are likely to repeat i.e. defintions, descriptions..
Like describe translation, transcription, and active transport. 15 marks. They're sometime after 2005.
The specimen papers on edexcel.com also have PLENTY of useful questions that weren't in Jan. 2009 and thus could possibly be asked.
And of course, the rest would be using your notebook and texttbook.
Besides, A in 2009 Jan edexcel Biology was 52 out of 80, an incredibly easy mark to get.
It might be even lower now that more people are taking the test.