You get good and bad in every trade, that's how life is.
Be professional, look smart, clean signwritten van and be nice and polite...and have a laugh!
If I ever have a wary pole customer, I clean one downstairs window for free and come back later the same day.
I show them how good it looks, give them a bit of chat and give them a fair price.
If they don't want, then I don't want them as a customer.