As said above, you've got to choose a reputable lass. Take recommendations from your trusted buddies on here.
I've not done many outcall punts but I'll say this, the ones i have done I chose recommended outcall only prossies. It's a rare punt for me and seeing one that I've had my eye on but rarely get a chance to podge appeals to my seedy nature
All in all, I prefer incalls though, I can walk, cut it short, refuse or stay my full time.... All keeping my anonymity intact.