Here are some drawing exercises I've been doing recently.
This is the River Bed Exercise.One of the things that I really like about drawing is that you really only need 2 things to draw (or 4 things if you are a pedant and need to include a pencil and paper in this list). You need an open mind, and persistence.
The exercise below looked like a load of old twaddle to me at first. I found it hard to understand what value there might be in it. But, that is no reason not to try something, so long as you can ignore your initial prejudice and get on with it with an interested and open mind.
I learnt a lot of little things whilst doing this exercise. It's hard to explain in words exactly what it is that I learnt. I learnt that I am more comfortable drawing from one direction than the other (although I can't remember which is my favoured direction). I learnt that you can make a real moving shape out of scales if you know what you're doing (which I don't yet). And of course, this exercise was much more fun - and intense - than I assumed it would be.