I strongly believe that if you use the ASI to identify the stall, you will miss the stall warnings.
Yes, under a majority of conditions the ASI will indicate approximately when the stall will happen, but it's like relying on the Tachometer (fixed pitch) to tell you if you're climbing. The tach will "slow" slightly when climbing and increase slightly when descending under the majority of conditions.
To understand the stall, you have to fly at the stall "speed" (angle of attack, but for that for that aircraft, with that weight loading, temperature, altitude, tach speed, etc, it will equate to a certain speed) aircraft condition for a while until you get used to the feel of it (in that aircraft, with that weight loading, temperature, altitude, tach speed, etc). Do some turns, find out how it affects the stall. This was a big part of my training as far as I can recall (it was 20 years ago), and it's been a part of every aircraft checkout I've ever done. Even when training on a twin, it seems like most of the training was single engine close to the stall speed.
Gliding would be a great way to experience it (I never have, but would like to some day), but it would be limited to the specific aircraft you're in.
If you're using the ASI, or are not comfortable with stalls, or not comfortable with spins, tell an instructor who is comfortable with spins, and go do some "ultra-slow" flight, stalls and spins. (OK, in todays aircraft you might only get to do spin entry) You'll be amazed at how much more confident and comfortable you are flying the plane.