The best advice I was given was to try and go to a school that is accredited and makes financial sense first. After all, in the end we will all be OTR's once we pass the NBCOT. By being accredited, it is in their best interest to teach the same information that a top program is teaching. Second criteria is think about where you would like to practice after you graduate, many of the OT's I shadowed and the OT's who are friends of mine were offered jobs by the last place they did their fieldwork.
Attending a program that is near where you want to end up practicing can be very advantageous as many of the fieldwork sites have well established relationships with your program. Even being a student at a top program like USC, they said that getting fieldworks in the Bay Area would be hard because they had to compete with SJSU, Samuel Merritt, and Dominican grads.
As far as advice about narrowing your search, it is really about where you can picture yourself working afterwards. I only applied to two schools (USC and SJSU) because I lagged, but I happened to get into both. My plan was to apply to major metro areas that I would want to work at though, (NYU, Columbia, BU, UWash, Puget Sound, UIC, and UNC). Right now I am trying to limit my costs because total costs of going to some OT programs are ridiculous compared to what an OT can expect to be making for the first few years out. If you are trying to not be 100k in debt, only apply to public schools in your state of residency and hope for the best.