Try using Aura Whisper or Detect Life to find--works much faster. I usually just sprint away in one direction or another and then see if I'm out of range. The most annoying spot this happens is by that road and bridge intersection where the Khajiit caravan sets up outside of Markarth, because there's almost always slaughterfish in the river. I just sprint up the hill past the farm and then usually I can fast travel from there.
Recent worst feeling: started a new character thinking I'd give the DBH quetline a second chance and then a random DB assassin attacked my character on the road and I recall why I hate the whole DHB thing. So I decided it's just so much more fun to kill Astrid and take her boots as I can go storm and loot the sanctuary, loot the place ad be done with these idiots. That way I have my muffled boots and no DBH drama or quests to be hassled by, and I can get on with what I like in the game.
I hate that there's a whole faction in this game that I just see as being better to destroy in one short quest and be done with than actually play out to whole quest line or let live as part of the overall Skyrim immersion. I kind of feel bad about that, like I'm not being a good sport. But hey Bethesda, next time try making an assassin's guild that isn't really just an annoyingly pathetic dysfunctional family who deserve to die more than the people they're hired to kill, 'k?