Before doing your pencil work in the study books you're using, (for example, The PowerScore LSAT Logic Games Bible) make copies of the pages which have actual test material on them. You don't need to copy the explanations and drills, that'd be the whole book! Just copy the 1 sheet practice exams for personal use before you start marking them up (there are about 21 practices in the Games Bible).
That way you can mark it all up to hell in the book as you're learning the game strategies; then later on in your study cycle when you come back to review these practice tests, you'll have fresh copies to work from that are unbiased from the remnants of your previous scratchings. This goes without saying, but let's say it anyway because I'm a dork: You can staple the sheets together and drop them in your bag so you'll have a little something to work on whenever you have extra waiting time while you're out and about. Of course I've yet to actually do this, but there may be some time in the foreseeable future when I'm waiting at a lunch counter and feel the need to drill my brain with the LSAT. It could happen. (This is also a good strategy when it comes to taking the full length practice LSATS: make copies first, then keep a personal scrapbook of the questions that you typically have problems with so you can work them over again.)
If you do enough practices and tests in the interim--unless you have a photographic memory--its doubtful that you'll still have the answers memorized from these early practice tests by the time you come back to them. But with repeated use of these and all the other practices you feel you can do, you WILL start to recognize the patterns of the question types. The makers of the LSAT only have so many types of tricks that they can throw at you, so they just keep using them in different ways. AND that my friend, is the key! Recognize all the tricks in their bag and you can ace the LSAT!