Believe it or not, SKILLS is the thing I find in greatest shortage. And plain old craftsmanship. It would be great in my eyes to hear more pitches for blower door testing, duct sealing, more willingness to consider the "V" part of HVAC. I think there is a potential for getting "up-market" by offering tests, measurements and reports which meaningfully tell the HO what's going on. Being able to make a smooth referral when it's something you don't consider exactly up your alley (e.g. I see eyes glaze over when I try to talk about humidity issues), would be a plus.
Humble things like doing ESP measurement, after explaining to the HO what it means, I think would help sell many ductwork improvements. Since 3M filters are supposed to be the HVAC guy's nemesis, would it be too much to procure and deliver some of the *right* kind as part of a year-round service contract? After all most HO's just want to not think about HVAC issues.
I think phoning the HO a couple extra times per year, fishing for feedback and problems you can help with, might pay off.
Hope you can work some of these into a business plan.
Best of luck -- P.Student