Years ago I used to work in a white shirt, grey suit and tie -- the only thing I needed to choose is the tie. It was kind of boring. Today's work environment has changed.

When I visit a provider, I always wear my best causal clothes. Always in jeans and nice underwear. I wear a jacket on first visit, but not for regulars. But that's just me.

As for providers' response. Almost all providers compliment at least an item in my attire. If not the shirt, it's the underwear or the shoes. I think there are more creative possibilities with causal clothes than suits. I can't tell the difference in treatment because I haven't tried experimenting with anything else.

I think T-shirt and jeans are okay as long as they're tasteful and you're clean.

I enjoy well wrapped presents. The ones that make the extra effort do get more aggressive ribbon  tugging, wrapper tearing and fisting of the pretty paper into a ball and slam dunked into the wall during the first orgasm...the second....

Attire does not matter at all.  You're not gonna wear it during the appointment, lol.  I've come to appointments dressed in plain street clothes, and the provider seemed fine with it.