I always spend at least a little time looking for the other side of a single. In my experience, I will often find other sheds in the same area. It may just be where I live, but bucks seem to winter together in little pockets. (the bulls too) If I find an antler, I will almost always find another if I look. However, it is not really common for me to find both sides off the same buck. As an example, last year, I went to a new area. I hiked for a total of 4 hours. 1 hour in, I found a brown antler, I hiked around for another hour and found 4 more, none were matched up and they were all from differnt years. One more brown, one from the year before, one two year old and one that was 3-4 years old. I then hiked for 2 more hours and found nothing. But because I looked around, I found a consitent wintering hole for bucks. If I would have just kept walking, I would have had a 3+ hour hike with only one antler. I'll be doing the same hike in a week or two and you can guess where I'll spend most of my time. Hopefully I can match up a few this year in that area.
Anyway, that's what works for me.