My own experiences, FWIW. I've done this three times, two very successfully (and those two remain good friends). However each time it was a case of converting an established SP relationship to sugar-daddy status. I can't imagine being able to do it cold, but that seems to be where you are starting.
For me the best candidate for this is an SP who is at the end of their "woo-hoo, this is such great fun!" phase (a year or three into the biz) and is approaching the "I can't keep doing this forever, I gotta get a plan for my life" point. Of course, some SPs never get to that point until the market forces it upon them. So, you start with an SP who you've seen a bunch and you genuinely like who wants to go back to school or otherwise start a career - sugar baby is an awesome way to transition between those two lives.
Set her up with a place to live and maybe tuition, in exchange for a pre-determined amount of playtime. Keep it well defined but simple and even though it is an arrangement keep it fun & casual. Agree on the ground rules way up front, this puts the girl at ease as well.
Now to limit your downside. Don't put anything in your name or put yourself in a position of fronting any money to the girl. This means that you pay rent and expenses AFTER fun-time. The lease is in her name, and the deposit comes from her (possibly funded out of hourly time with you - this worked well for me).
At the risk of over-generalizing, SPs are generally hot girls with poor self-discipline, money management, and planning skills. So don't expect them to have self discipline, manage money, or plan. They are also just girls, which means they've likely been raised to think it's cool to change their minds on a moments notice whether they've committed to an agreement or not. So always think in terms of what happens if she just bails on the arrangement totally, where is my risk?
When this works it is so great for both the SD and the SB, a real win-win. The pitfalls are easily manageable, but tough to see if you haven't been through it - that's what TERB is for though.
i enjoyed my times as an SD, and would do it again in a minute if I found another candidate.
Good luck - KK