Dear Dana,
If you were going to come down for a visit, you would want to post to the Seattle boards (or whatever city you planned to visit) about a month in advance, to let people know the dates you were coming, and perhaps a reminder post or two in the weeks before travel. It's also a good idea to let people know what area of town you will offer incall (Downtown, Eastside, North Seattle etc.) Helps clients to plan. Also, post where they can find reviews of you. People can start doing their research on you, and emailing or calling you for bookings, and you can start to fill out your schedule in advance.
As far as screening goes, it depends on how rigorous you want to be. Some providers do minimal screening, and take clients without background checks of any kind. Others ask for referrals from other providers, or contact information such as name, employer and contact number. Some who tour ask for upfront deposits, to help reduce no-shows. This is entirely up to you.
The trade off is this: the more screening information you ask for upfront, the more you may turn away gunshy clients that are unable or unwilling to provide info. Same with deposits. On the other hand, the less screening you do, your clients are less accountable, and you could get a bad client, or ripoff. You have to do what you feel comfortable with. If possible, try to talk to other providers who tour here, they might be willing to share info and tips. Jude, Bella of PDX, Baylee, and Ciera are a few women who do regular stops in Seattle. (Once every month or two). They might have some beta for you.
As far as business risk goes, that is harder to gauge. Again, this is an active area, and there are plenty of men always looking for fresh talent. But no-shows and cancellations are also a reality of touring (and this biz in general), and who knows who or what you'll be competing against on any given dates (other touring pros, seattle events, boeing layoff announcements).
I think your first visit you could expect your business to be moderate, you might just break even on expenses (luckily, hotel and travel is cheap right now). But if you are able to book with a few men that review, and your name gets out to the crew down here as being solid, by the time you make another visit, you'll have far more bites. I know Jude has regulars that make efforts to hook up with her when she comes down. If you were to get a few of these guys, then add in new clients or short-notice guys to pad out the visit, you'll do just fine.
Hope this helps, and maybe we'll see you soon.
Your personal sweaty studhorse forever,
iceman