Or you could go on the ques you already have such as:
Noise, slower you are the less noise
Control pressure, slower you are the less pressure
Control efficiency, slower you are less effective
Angle of attack, position of the nose compared to normal flight
All these things add up as total aircraft response, one alone can indicate
All these things vary from aircraft to aircraft to some degree, to know the aircraft your flying is very important. If you only fly half a dozen times a year you are going to be more than rusty(Apologies to Rusty, I don't mean you 😁). A switched on experienced instructor should be able to teach these things. I do think a simple AA indicator in your line of sight would help you recognize all the other things that indicate slow flight.
I'm not saying totally avoid looking at your airspeed indicator just listen to what the aircraft is telling you. After some practice you can approach without an airspeed indicator safely.
Fire away!!!!!