Try to use one coal on the rim of the bowl and a windcover. Or the other thing is, to break the coals in halves and use 2-3 of them on the edge of the bowl. The windcover is a great thing, can help you a lot. If there's not enough heat you just throw it on, if there's too much heat you just take it off. Play with it a little bit, practicing is the key
The other thing can be, that you put too much tobacco in the bowl. Leve a gap between the foil and the top of the tobacco. If you use normal foil and not Heavy Duty, than i would say try to use two layers of it.