Summertime and first few weeks of school are great, as papichulo said..
So make sure you pick your "seasons" properly.
Also sarging there with wingman is helpful, so if you have wingman that are truly down for this, work out a strategy. However, sarging alone is also not too bad, just look like you're on your way somewhere and got distracted, and just approach her. You can start at one end of the campus and simply start walking and approach every good looking girl you run into and chat her up.
Stop by the library and hit up every floor and make a few approaches there as well. Get your digits and be on the way. Continue to the other end of the campus, stop by the student union building (usually they have caffeteria there, college stores, shops, what not), and make a bunch of approaches in there too, and keep on moving..
So after you have made your round, you should have spent no more than an hour and maybe hour and a half there and walked away with at least 5 or 6 numbers (maybe not as many in summer if you don't run into too many girls that meet your standards). But the first week or two or school, you should go there and should be getting no less than 5 or 6 numbers, as there should be girls EVERYWHERE, and you can keep approaching as no one is really paying attention to you, everyone is busy with them selves and occupied thinking about what people are thinking of them or are busy interacting with others.
So if you start on one end, and just make your round, you should run into TONS of girls, might not even be a bad idea to get a school shirt.
Later, try to bang these girls. If somehow someway you end up developing a relationship with one of them because she is totally awesome,, just tell her that you dropped out to pursue your other goals
