By paying attention to wind direction and areas of probable "lift" from thermals or upslope air movement.There is no point in using them outdoors, as they are in the air for quite a long time, but the flight direction is completely random. How did you solve this problem with your models?
First, I would trim a large (1-2 M wingspan)
glider to fly in a very gentle turn, so that in still air it would circle within 300-500 M of where I launched it.
Second, I would launch from the upwind side of a large open area, so as it circled it would drift into the open area.
Third, I did a lot of running to keep the dang thing in sight when it threatened to liberate itself from my posession. I have retrieved gliders from trees, rooftops, rivers, the tops of parked semi trucks, a barnyard, and a baseball park grandstand. I was a nordic ski racer and jumper and a track and field athlete in high school, so running came naturally.
All that experience in second guessing the behavior of the air became valuable later in life when I became a flight instructor in gliders.