I think it's hard to prepare to be in the top 10%. If you work hard, that alone will get you to the top half of the class. If you add some natural ability, you can get yourself to the top 25 or 30%. To get to the top 10%, you have to be lucky. To be in the top 10%, you either have to do very well in the majority of your class, i.e. get As, or you need to beat the median in virtually every class. So you either need to have a lot of stellar test days, or you need to have all good test days.
A law school exam is based on confidence, so you need to know what will rattle your confidence. More than one law student was convinced they were going to work themselves to the top of the class, only to pick up a practice exam too early in the semester, wasn't able to answer basically anything on it, and then freaked themselves out for the rest of the semester.
Understand that you'll have good and bad days when studying and try to work with that rhythm, not fight against it. You want to treat law school like a job in the sense that you prepare yourself to work 8-9 hours every day, but that doesn't mean you can't check out early, or stay late. I worked until midnight some nights and other days I didn't work at all, unless I had to get something read for class the next day. You have to have the right attitude though, you can't get discouraged when it's a bad day and you're just doing the minimum.
Try to frontload the work. It's easier to pull back a little bit than to catch up. If you get behind early, fall break (if you have one) is really the only time to catch up.
Just try to arrive at each test relaxed, confident, and prepared. Law school isn't a crapshoot in the sense that if you work hard, you'll succeed, but to get the type of grades you want, you have to be incredibly lucky.