I have found that a common concern among painting students is their ability to draw. I regularly tell students to keep a sketch book, jot down their ideas when they have them so they will remember and have something to turn to when they're facing a blank canvas. And, more often than not, I see a look of fear at that suggestion. "But I can't draw," they'll say. And, while most of the time, I don't even think that is true, and, while I do think drawing is the foundation of painting and there are real benefits of learning it first, I don't think the ability to draw well is necessary to jot down ideas.
Now, I can draw well. I studied classical drawing for years. I copied Bargues until I was blue in the face (google Charles Bargue if you don't know what I'm talking about). However. I sketch my painting ideas on sticky notes and in the corners of other sketches. I use scribbles and stick figures. They are ugly as sin. And it doesn't matter--all that matters is that I've captured the idea I want to remember.
I think the biggest fear students have of drawing ugly drawings is that someone will see them. So I'm sharing mine.
Here's a Bargue drawing from when I was in school as proof that I at least know which end of the pencil to hold:
And now here are my sketches, followed by the finished paintings they led to:
Now, go out and capture some beautiful ideas in ugly drawings.