I like to use the little paper cups of various sizes.
Plastic cat food containers with drain holes poked in the bottoms do well for smaller plants. Of course, tomatoes and peppers need larger ones. I have a few larger peat pots that I’m going to try with summer squash to try to beat the squash vine borer season (as if there’s ever an off season). In Minnesota, the svb season is the last week of June and into July. Don’t know how that relates to TX but it may be that I can get a few squash if I start them indoor early.
http://www.extension.umn.edu/garden/insects/find/squash-vine-borers/
Also, to kill svb, when you see it’s been chewing on the plant, slice the vine lengthwise with a knife until you find the little monster. Do a Kim Jong Un on it. Then pack the vine with soil and it’s supposed to be a happy vine again. And, I’m going to move them outside the main garden because squash bugs will overwinter.