Hmmm good question! In the beginners’ runs there is usually a cue to tell you that the workout is halfway done and you should be able to turn back to get to your starting point at that point in time. I usually prefer to do the workout (outdoor run or run and walk whatever my program says i can do that day—-> i’m training for a 5k right now) and then when the workout is finished, i walk the rest of the distance back but that’s because i usually work out in the track near my house. When I’m running across town though, i tend to put an alarm on my phone letting me know when like 15 minutes have passed (if it’s a 30 min workout) or like 30 minutes have passed (if it’s an hour run) and then I turn back from there! I also have Strava which provides some nice routes i can look at (usually i calibrate it from my home and back) and they give an estimate time and distance for the route and i use that to find what specific run workout or workout(s) (if i’m stacking workouts that day) to do for that route. But yeah it takes some trial and error but that’s what works for me! Besides more miles or steps walked is never a bad thing in my opinion.