I've struggled with this for the last forty years.
I want to hang something on a drywall wall, and I want to use the studs instead of drywall anchors. I have the damndest time finding the studs reliably.
There's the time-honored and lo-tech method of tapping on the wall and listening for different tones of hollow wall vs solid stud. So, I find a stud that way, then measure 16" (or 24") on either side, tap there, and hear a hollow sound. At that point, the process becomes random and seldom 100% accurate.
I have several electronic detectors and their performance is spotty as well. I can scan the same spot three or four times and get three or four different hits over a space of about four inches, too wide to be a single 2x2. (No, I'm not finding a doubled stud.)
The most reliable gadget I have is also the simplest: a small plastic horseshoe with a magnetic pointer suspended between the open ends. You move it over the wall until the pointer moves, at which time you know you have detected a nail head and are on a stud. The problem with that is that nail heads are a very small area of a wall and it takes a lot of systematic scanning to find them.
I invariably end up approximating where I think the studs are, then punching trial holes with an awl. This leaves me patching lots of little trial holes when I'm done.
Any suggestions?