Some thoughts.. as with any instrument there are different views / opinions on what is the right technique/method. As far as I understand it there's basically two, the classical "lower your adam's apple, push from your stomach and belt it out" approach, where these position of the adam's apple is designed to help you not hurt your voice. This is the realm of opera/classical singers, Musicals and Town Choirs etc. Then there are more modern "speech level" methods which focus on developing the voice naturally by training it through various exercises, which also help to protect the voice. African men who seem to be able to sing so naturally without much effort are most likely using these "speech level" methods. Unfortunately when looking for good singing advice for myself, the teachers of each method claim that following the other method will hurt your voice. Perhaps a balance between the two is where the truth is to be found, whatever works. But you find the same thing with any instrument.
So here's a more "speech level" method I found that focusses more on right technique and control and breathing.
Search for the Arceneaux Approach on youtube, and website is:
The Arceneaux Approach - Sing With Power and Freedom
I disagree on one point in these singing tips given here - opera singers are not fat because they use their diaphragm lol, there are many thin opera singers around. Two of the "three tenors" were not so big and fat like Pavarotti. I'm a brass player and trumpeters and any brass player use the diaphram as well, and don't all have fat bellies. The main reason why there are big bellied opera singers and brass players is because of all the beer drinking after a session and not getting enough exercise. Not because of using their diaphragm. If anything their stomach muscles should be tight and toned from using it, not fat. It depends not so much on how much air is being pushed through but how much air pressure is formed behind the note i.e. breath control is important and this is what these "speech level" approaches help with. With proper technique actually less air is required not more, "less is more" as they say. If you can sing well and with power and control with less air, that's a real advantage.