Great topic MM
Ok, its simple really
It all starts with your fire. Dont build a "flat" fire", build it as high as you can. This ensures consistant heat throughout your coals. Fires that are built "low" tends to be too cold.
Rule #1
Buy quality meat. If you buy second grade meat, your starting point is all wrong
Rule #2
If you cannot hold your hand 20cm from the fire for ten seconds it is too hot!!!! Have another beer and wait before you throw your meat on there!
Boerewors and steak.
Hot Fire, braai quick. Depending on how you like your steak done, depends on cooking time.
To tell how well a steak is cooked do the following:
Put your pinkie tip on your thumb tip. With your other hand, touch the base of your thumb, in your palm. The "stiffness" you feel there is how a well done steak should feel when you touch it. Going down with the rest of your fingers (touching your thumb tip on their tip)will indicate degrees of meat that is less cooked. Your index finger touching thumb being rare...
Chops:
A medium fire works well with Chops, but never ever leave them unattended. Because they are fatty, they tend to spark fires the minute you turn your back.
And please please please... Never ever kill the flames with water, your chops are likely to get tough. Use beer, or move the chops to another part of your fire
Chicken:
Medium fire... slow going and it takes a while.
What I do with my chickens is to put them to the side of the fire, not directly over the coals for the first ten minutes. When the fire is nice and cool, I give it about 20 minutes or so directly over the fire. It is important to note that you must not blacken your chicken. If your chicken goes black over the coals, put it to the side and let it go there a bit longer.
Keys here are:
#1. Slow,
#2 long
Ribs:
Precooked ribs go with warm fire but not too hot, braai quick until warm throughout and nice and brown outside.
With uncooked ribs follow same rules as you do for chicken
The biggest challenge with braaing is when you have a combination of the above...... To become a braai king takes practice and time. But hey, sometimes you get it right, sometimes you get it wrong

experiment, but this should serve as a good starting point