Dry conditions do not make dust control optional
Sanding joint compound and smoothing a broad ceiling can produce fine dust that travels beyond the work area if vents and doorways are not protected. Ask contractors what containment they use, whether HVAC returns are sealed during dusty stages, and how cleanup is handled at the end of each day.
For tall or vaulted rooms, request that access costs be included in the original estimate. Scaffolding or specialized ladders should not appear as a surprise once the crew arrives.
Make sure the bid includes the surface you actually want
If you want a flat painted ceiling, ask whether the proposal includes spot repairs, full skim coating where needed, sanding, primer and final paint. If the existing texture is painted, have the contractor explain whether scraping is still practical or if a resurfacing method would reduce damage.
Older or unknown materials should be evaluated appropriately before disturbance. A dry climate does not change the need for responsible material identification.