Would like to ask for opinions on how to get a proper haircut in a barbershop. Most my life have gotten mediocre haircuts and even grew my hair for while as I was relocating and wasn't trusting anyone with scissors where I was. How do you guys do it or what tips you have for any men wanting to get a haircut in a barbershop?

Agreeing with UFC_fighter. Be visual and help the barber visualize, really helps him giving you the right haircut.

Proper is a highly subjective word, though I hope your intent is that proper be well cut in that proper style, that it may require the use of new products, and that it falls within the generally accepted boundaries of my lifestyle or culture. and that traditional (old school) styles are often regarded as most "proper". To get a proper haircut, I'd take along a photo of what I consider to be a proper haircut, and ask the barber for critical answers to the following questions:
1)  Will the cut adapt well to my facial structure?
2) Will the texture of my hair do well with the haircut in the photo?
3) How much daily maintenance will it require, and how would I style it each time?
4) Does the barber, overall, believe the haircut would be suitable for me (My barber knows me quite well)?
If my barbers responses are entirely favorable and acceptable to me, I'd thank him for his feedback and say "Let's Do It!", understanding there might be some time before the new look can be fully realized