If a provider is coming to your place, home or hotel, on a Saturday afternoon, what would you like them to wear to not draw attention from the neighbors, but still give you that first visual impression to set the mood? jeans? yoga pants? a skirt? something else?

come to my residence until I have seen her a few times.  Once they have your address, they can hold doxing over your head, so I would never have one come to my home that I haven't know for several months.  I'd rather pay for a hotel room and protect my privacy.  A relative small percentage of providers are BSC, but if you happen to get one, you should be thinking in advance about how much damage control you may have to do.  Whether or not your neighbor sees he in tight yoga pants where you can read her lips may be the least of your problems.

Wear normal outside clothes. Jeans, tshirt or what not. Blend in outside. Change to something sexy once inside.

We've met before.  Many times. I know her RL info so I trust her with mine. She dresses casually,  like she's running errands or meeting a friend for coffee.  
Like i said,  she's gorgeous so i don't care what she's wearing.  I'm in the mood.

I  prefer  not  wasting  the  Client's  time
during  an  outfit  change.

Doesn't a specific answer depend on where you live? Private house, gated community ... Hi-rise doorman building ... low-income tenement ... pop-up tent in the woods ...  
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I assume that most hosts would prefer to avoid attention: orange spiked Mohawk or something less noticeable? And so on.

I've seen a few providers that were BSC but that did not become apparent until I knew them for a while. They appeared to be completely "normal" until they weren't.

I can adapt in any environment. I dress accordingly and it varies depending on the weather & location. I prefer to be comfortable. If requested I will bring a pair of heels, but I do not put them on until behind closed doors. Casual & cool is the norm. I can get sexy AF once I am entertaining privately. Being a professional I can come in my scrubs if you want to make a wellness check house call. There's so many options if you have nosey neighbors.

I have gal's come to the house from time to time---whether I pick them up at their place or they drive I always suggest that they wear what is comfortable for them----and if asked----no "Costume Change" is needed----as an example---Jeans or shorts and a top is just fine----(Let's Face It......we have invited a young lady to come to the house----with the key motivation to get her out of whatever she is wearing----no need for a costume change)!

Come to my house…period! That makes things easy. I’ve seen providers in hotels in various degrees of sexy attire! However they have always blended in with the crowd enough to avoid any concerns about our activities.

She would have to wear something to blend in. She shouldn't dress like shes going to a 5 star restaurant or like she's doing a night on the town. Keep it cool,
But on a side bitch and moan note. If it was night time and she was meeting me at my hotel, then no yoga pants, no flip flops, no tee shirts,  and no... God Sake....no fucking moo moos

The client’s discretion is the most important thing when showing up to either his house or a hotel room, given that there are often coworkers at the same hotel. So I dress to blend in - maybe dress slacks and a blouse or sweater, or jeans and a jacket, depending on the setting.

I totally get that.  It’s always great when a provider arrives and we can go up to my room and just tear each other’s clothes off.  Not a fan of the costume change unless I’ve requested a special outfit.  Jeans, pretty blouse and nice shoes have always been fine with me at the nicer hotels in Vegas.  Blending in is what matters and thankfully most reputable providers understand this.