Not so sure about dressing smartly and clean van bit.
Bet 50% of my customers don't even look at the van and some, especially in Winter never see it.
Depends what you call smartly, I wouldn't expect a tradesman to turn up at my house in trousers, shoes and smart shirt.
I, personally, usually wear cargo pants, clean trainers and smart tee shirt plus crocs in van for when doing u/h but not carpets.
In empty commercials in summer I'll wear shorts.
Being polite is all part of the package and being on time too although can't always be guaranteed as I point out to people.