M has three pockets of negative space that look very much the teeth of a vicious animal, biting down.
In humanist designs, sometimes we see sloped stems. This helps balance out the sizes of the three teeth.
On occasion, in some geometric sans, the vertex in M doesn’t hit the baseline. This is also the case in monospace styles because it allows for a more narrow form.
Keeping the bottom teeth the same height helps in pretty much every style. Also, the contrast goes thin thick, thin, thick.
And other times, even crazier shit like this.
Sometimes, we see students pulling crazy ass shit like this.
An expansion m has branches that grow vertically out of stems.
In translation, branches join in a more perpendicular fashion. When contrast models change, we see things like joints change, but the same rules apply.
Actually, even when everything changes, the rules still apply. ✌