The London Lounge

I am thinking about having some traditional, cavalry twill trousers for wear with my blazer (and other coats for relatively casual, business casual situations).

I am curious, we trousers in cavalry twill, covert cloths, cottons, etc. (basically military and riding inspired trousers) traditionally done with flat fronts and plain bottoms? Any type of particular pocket confirgurations that were traditionally applied?

Many Thanks!