I live in the areas you speak of and there are so many variables esp. with fly fishing. To make the best of it, I would hire a guide that specializes in fly fishing for tailing reds etc. I can give you a couple of names if you want to send me a message.
Also, here is a video of a buddy of mine that caught a couple of reds in Port O'Conner Texas.
Mac Jank on the fly - YouTube