Seems like you just shoot for the best school you can get into. In addition, is a good method to shoot for applying to 7-10 schools - some slightly above your expectations, some in line and some as fall back schools?
For the most part, this is good advice. There are some more things to consider as well, though. If you don't care about moving or where you'll be working when you get out of law school, then balancing the ranking of the school and the cost of attending will be your biggest task. Note that if you want to work in a certain state or region, that attending a regional school can trump a large rankings advantage, to a point. If you want to work in Mississippi, for example, going to Ole Miss would be a better choice than going to a school ranked 30 spots above it. However, going to Harvard would be better (though overkill from a cost and stress perspective).
You may also end up applying to a lot more than 10 schools depending on your goals and your credentials. If you know you want to work in a certain region, there is a smaller list of schools that will make sense for you to apply to. If you could work in 5-10 cities throughout the country, then there could easily be 20+ schools that would be worth applying to. While much of the law school application process is straightforward, sometimes results can seem like a crap shoot.
As mentioned above, finances need to be considered. A free ride to a school ranked 10 positions lower than another one you would be paying full tuition at might be a good deal - or it might not.
Also, will you be attending full-time or part-time?