As far as holsters, it depends on your wardrobe and what is more comforable for you as far as carry is concerned (this assumes you have a CHL authorizing carry in TX). For those that regularly wear vests or sport coats, a shoulder harness w/ holster is reasonable for tucking under your jacket or in a vest. The NRA sells a couple of jackets with hidden pouches that also work in more casual situations. Also popular are hip holsters and ankle holsters for discreet carry. Depending on the size of weapon and season, any or all of those could work in TX.
Without permit, you can conceal in your car in TX (unless authorized for in-bldg carry by employers like Harrold ISD) pretty much anywhere except military bases and sporting event lots.