For the most locations in Tx,special attention isn't neccassary. Where ground is overly moist,ventilation is more benificial than insulation. Humidity is low in Western half so ventilation isn't critical. I wouldn't insulate crawl space but might insulate floor in upper Panhandle.

It's not clear from your post whether you are referring to a crawl space foundation or a home on piers without an enclosed crawl space. My remarks below assume a crawl space foundation.

Texas has four climate zones including three climate zones recognized in the International Energy Conservation Code (IECC) i.e., zones 2, 3, and 4, plus, according to a local expert, a "tropical-like" climate zone around Katy, TX albeit not one recognized in the code.

If your crawl space is a ventilated crawl space, you will be required to insulate the floor to the code-required R-value for your climate zone; refer to the International Residential Code (IRC) table R402.1.2 I suggest closed cell insulation.

If your crawl space is an unvented/conditioned crawl, you would need to insulate the walls to the R-value per IRC table R402.1.2 and per section R402.2.11 and provide ventilation according to section R408.3 I suggest closed cell insulation.