To be honest, the French exam is pretty simple compared to other exams. I could say the same thing for the Spanish and German exam since they're all pretty similar. But since I do French and Spanish, I'll make the post here.
This is how easy I personally find it. If you're looking to pass, this is the best approach. If you're looking to get an A, this could still be a useful approach with the least amount of effort.
Here it goes:
Make a folder for French, and make one section for your comprehensions, one section for letters, and another for the orals.
In the comprehension section, put all past exam comprehensions (use Studyclix of course if you want a quick and easy way to look through the exam archives for comprehensions) inside that section. Every week do a comprehension, or even every few days when you have the time. It doesn't really matter. It could be two weeks. As long as you get all of the comprehensions that have ever popped up covered. Even sample papers if you have the time.
This will 1) teach you some new words, 2) familiarize you with the comprehension layout and 3) teach you how to do comprehensions properly.
Refer to the marking schemes for answers.
In the letter section, you'll have the questions which are in the second section of the exam that ask you to write a letter, write a note, all that good stuff. Again, do these whenever you have time. But make sure you get a fair amount of them done. Also refer to the Skool.ie checklist for a list of those that should should practise: http://www.skoool.ie/skoool/examcentre_sc.asp?id=816
Finally, the orals. Create a section for those where you'll put all the questions that they may ask you and practise answering them whenever you get the chance. If you are bringing a document, put it in there too and memorise it the best you can and prepare the questions they might ask you.
As for the aurals, it's just hoping it's not too hard. All I can say is go to the past papers and listen to the sound files included. It's not that hard. Nobody can predict what vocabulary could come up which is the ridiculous part of Leaving Cert French that I personally despise. Memorising things we don't even know will come up? Nope. I'll pass.
Anyway, there's some tips for your LC French. It's all up to you in sixth year. The teachers can't help you prepare for the French exam at this stage so that why I'm offering to help.
Good luck next year, we'll do fine I'm sure!