Generally speaking, outcall has risks (more for her than you) but it happens safely all the time. Just use common sense and good mongering practices:
Find providers who actually do outcall - they know how to do it, they pack for it, dress for it, they'll communicate their do's & dont's, they'll have a good sense of safety, and will put you at ease. Many outcall providers will only visit hotels, not private homes.
Use reputable providers who have been reviewed for the services you're looking for - don't book an outcall massage and expect extras unless you know she provides those extras, or book a FS provider and expect a quality massage. Shop for what you want so you get what you pay for.
Make sure your place is safe and approachable - if you were her, walking up to your door, would you feel safe going in there and getting naked with a complete stranger?
Put valuables out of sight before she gets there - she's most likely not interested in robbing you, but don't leave your wad of cash out on the dresser anyway.
Use your big head and don't be a jerk.