2) Add detailed drawings.

Just like with the original stick-figure drawings, you can make these really sloppy. No need to spend a ton of time on these, as you're almost guaranteed to have to touch each of these frames again. It's possible to get the hands, feet, arms, legs, etc. pretty much right the first time, but I definitely don't have the talent to correctly draw in secondary animation for the shirt or pant legs in one go as I trace over the stick-figures. You can see I've tried to draw in some secondary animation for the pant legs that is mildly successful because the movement is pretty simple down there (cuff stays high when foot hits ground, slaps downwards on the next frame). I didn't even try to make the shirt flap. You can also see that I left the line for the waist in there even though it should be under the shirt. This is useful so that you can judge the center of gravity, and the motion of his mid-body a little better without the clothes messing you up. It's easy to erase things later, so it's not a big deal to leave helper lines and marks around.

3) Keep on tweaking