Where is there a good place in southeast Texas to catch your own shrimp for bait legally?

get a TPW book and study it well. all kinds of rules and they change yearly. if you use a trawl, you'll need to purchase a tag at the TPW office. many places are off limits and the season opens and closes several times. also the size of the net and doors and the size of the mesh. mind boggling. even using a cast net is confusing.

Smooth move is exactly right. The recreational shrimp laws are the most poorly written laws I've ever seen. Very hard to understand. Honestly, I think they make it confusing on purpose. TPW really needs to make a map of where you can and can't shrimp. I've seen people get tickets for cast netting shrimp in areas I thought were legal. I'm big on catching my own bait but I leave shrimp alone.

You can cast net them. Must have a fishing license and has to be between sunrise and sunset is what I recall. At least for Texas. All the rest above is correct.

I used to throw a cast net for bait, including shrimp, in the marshes and estuaries a long time ago. Back then if you were just getting bait the wardens would just check your coolers and let you be. As long as you only had a quart or so things were fine. But I did see guys with big coolers of shrimp get tickets. For the most part if you are doing right, using sense and being respectful the wardens treated you as such. I don't throw a cast net much anymore though.

Its probably illegal