I started as a helper on a small insulation crew, hauling hose and bags up into hot attics and learning from people who were fussy about the details. In 2013 I opened Quality Aliso Viejo Insulation Services as an insulation contractor in Aliso Viejo, and I still climb into most attics myself because that's where you find out what a house actually needs.
Most of our calls come from homeowners with hot upstairs rooms or a power bill that keeps climbing, plus a few property managers. What I care about is the order of the work, because insulation laid over a gap or a damp spot just hides the problem. I'd rather tell you a job isn't worth doing than sell you something you don't need, and if the real trouble is a roof leak or old insulation that looks suspect, I'll say so and point you to the right trade instead of working around it.