A drop of sugar syrup on a plate near where they're landing will usually get and hold their attention - just a drop, too much can become a glue trap - and slow movements while you take the plate outside will typically not disturb them. Then you just need to bring the plate back in later, once they're done with it and have gone about their occasions.

Solitary wasps tend to be a little twitchier than social ones, but I've had this method work as well with both sorts. On the other hand, I understand wasps well enough not to be frightened of them and they seem to like me pretty well too, so I suppose I can't vouch for good results in all circumstances.