Richard Evans wrote:
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?

As others have said the electronic units work if you go slow.
Many times I use a tape measure measuring from an outlet. There is
almost always a stud on one side for the other of an outlet or switch.
Take the cover plate off and look for the stud. If you can't see it then
use a nail or screwdriver to probe in and find which side the stud is on
and then measure from there.
Kevin