the search function on tumblr is kind of bad (but where is it good these days) so the best way to find stuff you like is to start from one thing you like and look at all the peoples blogs who liked or reblogged it. so you kind of need one starting point but then you can go out in a sort of tree if you know what i mean, working outward from the one thing you like, to people who liked it, to other things they liked/reblogged that you like, and then looking at the blogs of people who liked that, and so forth.