I will never criticize a man for fishing. The lack of success is unfortunate although my guess is it will only be temporary.
You have a lot of nice equipment to go after those pesky fish. My only minor suggestion might be to go the other direction on your equipment. Pick up a nice whippy ultralight rod and spincast reel. Then get you some small baits. If you can see small fish, you can bet there are bigger ones watching the action.
Have fun out there. Jim

Bass

Aww...come on Moon! Spincast reels are just fine for someone new to the sport.

But anyways. Ok, one of your biggest mistakes is when you are fishing. I've fished the hill country for years and know the conditions pretty well. Moon is dead on about the fishing times. Between 10 and 3 is when the morning bite is ending,the sun is highest and all your big fish, especially bass are hiding in the shade of trees or in the undercuts along the bank. Try it in the morning or an hour or so before dark. Now when it is dark if you have a little moon, get out a top water and throw it. Let it sit a good while before you move it at all. At least a minute, then give it just a little bit of a tug, enough to get a hungry bass's attention is all. Wait again for a bit. Then make it swim a short distance real easy like. I assure you there is no more thrilling way to fish than topwaters on a moonlit night. Now another thing to keep in mind is that as you stated, the water is almost always real clear in the streams and rivers in that area. So the bass can see you unless you are pretty stealthy. Try sneaking up behind the tall reeds that are on the bank in a lot of places. Keep noise to a minimum, especially if you are with other people. Nothing will kill the chance of catching a big bass like a little noise. They just turn the other way and go. That's how they got to be "big." Go down to the river after dark with a flashlight and you'll see how many fish are prowling about. Especially catfish. There will probably be a gathering of them directly below the low water dam. And one other thing. If you absolutely want to catch a nice fish there, catch you a few small bluegills...say 25 to 50 cent piece size and fish about 3 feet below a small bobber with a small split shot weight about 10 inches above the hook. This is the main food of these fish. They will go for it. Also, here shortly there should be plenty of those big old yellow grasshoppers about. They are like candy to bass and catfish. Hope I'm not too longwinded. Good luck.

EGAD Davey! You must have been lurking about watching me fish the Hill Country back in the day when I lived in Austin. You just read him all the rules and regulations that apply! WOW!
Now, with the "big ole yellow Grasshopppers",If you want cats, catch those hoppers, smush their heads but leave em on, impale them on a hook and tight line them in the holes where you can't see the bottom in those crystalline waters. Old Russell Tinsley trick(he used to be the outdoor writer for the Statesman in Austin).

Love fishing those crystal clear hill country streams(at leasst back in the day when they had water in em.

Rudy