Marketing is a different animal, however being a single inspector firm I prefer the same attire as I would doing an inspection.
If I were multi inspector firm than a tie would be in order.
Collared polo type shirt with company name and some type of Jean or cargo shorts and tool holder on belt. Flashlight ring with mag light and camera on hip,
Sneakers for safety and climb-ability.
This is my attire.
Love the shot. You better watch that pinky with the beer.
Hell that looks like a “tin” can. 
the only people that wear ties here are detectives and lawyers, oh and preachers. Pensacola is a very casual atmosphere, lots of tourist trade and related businesses. Anyone with a tie looks out of place, even suspect…refer back to the “detectives and lawyers”.
When I was with the CIA I had to wear a suit & tie every friggin’ day, **** if I’m gonna kowtow to that **** as an inspector. 
Worked fine, my birthday suit still fits.
Collar Shirt… No Tie…
Joe,
Who are you kidding, we’ve only seen you in fast cars & custom made suits. 
…
Communication is 80% non-verbal. What do you want to communicate to your clients? First impressions are lasting. So govern yourselves accordingly…
90% of home inspecting is half mental.
Blaine writes:
I agree.
I wear a Speedo and tool belt. It’s a Florida thing.
I am soaked with sweat and get far to dirty doing inspections to wear a shirt and tie. Between crawling attics and working in the Fl heat it’s just not for me. I wear shorts and a polo shirt with logo. No jeans though. Just my opinion.
I put on ladies nickers While I am cutting hair and break out in song. "(http://www.youtube.com/watch?v=5zey8567bcg)http://http://www.youtube.com/watch?v=5zey8567bcgnd I.M OK"
I put on ladies nickers While I am cutting hair and break out in song. "*(http://www.youtube.com/watch?v=5zey8567bcg)