Houston sits on expansive clay. When it's dry the soil shrinks, when it rains it swells, and the slab under your house moves a little with every cycle. Drywall is the first thing to show it, usually as diagonal cracks running from the corners of doors and windows.
Hairline diagonal cracks that come and go with the seasons are cosmetic in most homes. The fix is to open the crack slightly, tape it with mesh or paper, float it in two or three coats, and match the texture before painting. Done properly, the repair disappears and may stay closed for years.
Cracks that keep widening, doors that stop latching, and gaps opening between walls and ceilings are a different story. Those point to foundation movement beyond normal, and a drywall patch will just reopen. In that case we'll tell you to get a foundation evaluation first and come back for the drywall after.
Ceiling stains and soft, bubbling drywall are almost always moisture: a clogged A/C condensate line in the attic, a roof leak, or a bathroom above. We cut out the damaged section, let the framing dry, fix the source, and replace the board. Painting over a stain without replacing wet drywall just hides it until it grows.
Nail pops and small holes are the easy ones. Reset the fastener, add a screw beside it, fill, sand, texture, paint. If you have several rooms with small damage, batching them into one visit is far cheaper than a call per hole.