Looking for advice on choosing reliable HVAC and fire-safety contractors in Pakistan

I run a service company in Pakistan called Workman Services (workmanservices.com.pk), and one thing I’ve noticed over the years is that many clients aren’t always sure what to look for when choosing a contractor. It often leads to misunderstandings, delays, or work that doesn’t match expectations.

For those on the client side — whether you’ve hired contractors for HVAC work, fire-safety installations, renovations, or anything similar — what have you found most important when making your decision?
Do you rely more on past project history, certifications, communication, transparency in pricing, or something else? At workmanservices

I’m asking partly from a contractor’s perspective and partly out of curiosity, because understanding what clients value most helps create better working relationships on both ends.