Unlike rhododendrons, azaleas have growth buds all along their stems just under the bark....new growth will originate close to any cut you make.

While most don't require much in the way of pruning other than removal of weak or dead wood and whatever trimming is necessary to keep them shapely and within bounds - yours are looking a little gnarly :)

If you are looking for more compact plants, you can cut some of the heavier limbs back to a foot or so and should have new shoots develop to fill in the legginess. At the same time, shape them up to please your eye and remove anything leggy or twiggy.

Pruning now removes the flower buds for this springs showing - a better time to prune is immediately after they bloom. I have acidic soil naturally and don't fertilize these shrubs - they are not heavy feeders. I see you have a drip hose installed and that's good, you might want to consider adding a layer of mulch or top dressing of compost to conserve moisture, cool the roots.

Thinking Texas, my first thoughts were alkaline soil. But after looking at your pictures, the main problem doesn't seem to be pH, but rather poorly drained compacted soil.

First, azaleas need an acidic soil. If your soil is not acidic, which I doubt if it is, then you need to modify the pH. If too much modification is necessary, it is best to use a raised bed with a good acidic soil.

Second, but most important, azaleas need good drainage. If the soil doesn't drain properly, the roots start to suffocate and get root rot which eventually kills the entire plant. This is also best achieved with a raised bed.

Raised Beds: Azaleas need three things, acidic soil, drainage and drainage. If the soil is poorly drained or alkaline, a raised bed may be the best option. Azaleas have shallow roots, so the raised bed only needs to be 6 to 12 inches above grade. Create it by creating a mound or berm, or a raised planting bed using a retaining curb such as logs, timbers or rocks. It is best if the base is a material with good drainage like gravel. Then at least 6 of 8 inches of good acidic, well-drained soil above that. If you use a lot of peat moss or compost remember, the peat moss and compost will decompose over time to 1/2 the original depth, so make the bed proportionately deeper.

When preparing new raised beds in soil that is not acidic, the pH may be lowered by adding flowers of sulfur (powdered sulfur). Amounts of powdered sulfur needed to lower the pH of a silt loam soil to a 6-inch depth are given in a table on the website below. A target pH of 5.5 is ideal for most azaleas. Sandy soils would require less and clay soils would require more. Elemental sulfur is converted to sulfuric acid by soil bacteria. Therefore, in order for sulfur to work the following must be satisfied:

* Sulfur must be mixed with the soil to provide contact. (Around established azaleas, do not disturb the shallow roots. Sprinkle the sulfur under the mulch and then replace the mulch.)
* The soil must be moist
* The soil must be aerated (bacteria need oxygen).
* The soil must be warm for rapid bacterial growth.
* Time is required for the reaction to go to completion.

Here is a link that might be useful: How to grow azaleas.