In a place like Texas you may want to make sure you have some shade on the pond as well. I know you should do that everywhere, but in Texas, Florida, and other hellishly hot places shade is important.
Also, how cold does it get in the winter where you are? I know some parts have cooler winters than others.
Go with the best liner you can afford, we have had to re-do a pond a couple of times at my friend's place. Also go big with the filter be it DYI or store bought.
And once you dig and put the liner in, you may want to add the decoration/substrate before the water.
Oh and put the filter in an easy to get to spot.