Two Helpful Things

There are two things I feel have probably helped me more than anything else on improving my sketches. The first is Posemaniac's 30 second drawing exercise. Drawing form quickly and not spending a lot of time over-thinking everything too much greatly improved my quick-sketching abilities. I used to try and do at least 20 (10 minutes) of these sketches a day but recently I've really kind of fallen down on that, and I plan on getting back into that habit again. And if 30 seconds feels too daunting (or not daunting enough), you can always adjust the time in which the next sketch pops up, between 10-90 seconds, or there is the random pose viewer which will let you look at an image for as long as you want to.

The second is The Eyeballing Game. I find it useful for off-the-cuff perspective and helping to make things look right. Being able to visualize where a line is going and how to make something seem square or correct without the use of one, two, or three point perspective is also very useful for sketching more elaborate scenes. The 'center of the circle' exercise helped me make faces seem less lopsided (a problem I still have, just not as bad) by helping me realize where the center is. And like most things in life, the more you do it the better you get at it.