I took a year of "fine arts" at a community college years ago and I actually used to (and still want to) study concept art pretty diligently! It doesnt show in my cartoonery but I'm a little versed in colour theory and perspective and values and rendering and all that. If you look back at the original Horsewife comics you'll see they kinda suck!
So the only answer is Daily Practice!
Talent is a word that lives on the lips of the lazy after all
The hardest thing for me to draw is hands, hind legs on ponies, and the insides of mouths with the teeth and the tongue and all that.
...and elipses in the proper minor axis.