1. Find the sharpener and the good erasers** BEFORE sitting down to draw. Put the sharpener and erasers in a place that you can reach without getting up.
2. If you are getting too involved in your drawing and don't want to bother to sharpen your pencil, SHARPEN THE GODDAMN PENCIL. You will regret it if you don't. No, really, you will. Sharpen the pencil. Now.
3. If you are a lefty, start on the right side of the page. If you wind up wanting to add something to the right later, protect the rest of the drawing with a sheet of vellum.
4. If you are going to work on a drawing for hours, don't use the Staedtlers. They smear. Use the Tombows. They don't.
5. Do not draw the legs before determining the tilt of the pelvic cradle.
6. If you are drawing someone with male parts, do not wait to draw in the genital details later the way you do with female parts. This is because the penis blocks some of the view of where the legs come out of the pelvis. If you draw the legs first and then sketch the penis in later you are likely to discover later that you have misjudged where the legs begin and that you have to draw them all over again. Being that legs and feet take a hell of a lot longer to draw than a penis, this is very sad.
7. If the top half looks great and it doesn't need a bottom half, remember that a drawing doesn't always require a bottom half.
8. If you have not moved for hours, get up and shake it out. Also, do not get so absorbed that you ignore nature calling until it is shouting. Your body and (believe me) your line quality are suffering.
9. If it's getting on towards three in the morning and your drawing looks great except one part, just stop. You can fix it tomorrow or more likely not even remember what the part was the next time you see it.
**Throw out your shitty erasers. At best, they sit around fooling you into thinking you have erasers when you don't, at worst, you'll get desperate and use them and we all know that ends in tears (here both meanings of the word apply).
Now let's see if I remember to look at this next time I have to take a big break...