I have quite a few:
my first book I had to buy for school was Bert Dodsons Keys to Drawing. Great book on fundamental mark making, finding landmarks, drawing from life, and blocking in basic shapes and breaking objects down into fundamental shapes.
Drawing Lessons from the Great Masters by Robert Beverly Hale is absolutely key to picking apart pieces from old classical artists like Michelangelo, Da Vinci, and others, teaching composition and anatomy. Please pick this up, it is absolutely stunning.
For my routine on warming up I start with circles and lines, and I give myself about 20 minutes of time to really hone in on curved, S shaped lines, and straight lines, or as they call it "CSI" method. These are the most common lines you can find while drawing the human form. It also gets my head into a good spot to look for the simple lines, to look for the forest in the trees, if you will. Laying down good foundations takes a lot of time, and my art mentor described what we're trying to achieve here as mixing the mortar for that foundation, if the mortar doesn't stick, the bricks in the foundation won't hold together and we don't have a foundation at all. Give yourself those 20 minutes, don't be afraid to fill up your sketchbooks with "stick" figures that have a lot of expressive form and CSI lines. Good luck and feel free to reach out, I'm always happy to help!
Sam
for the 30 second and 1 minute times, you're not really meant to do more than find the main lines, and what I would do is keep your human figure to less than 7 lines. For the minute time, you can start to add ovals and circles to represent major forms. I wouldn't fret about "not knowing where to begin" with a 20 minute pose, you have everything you need, just start from the main dynamic line and build up from there!
Well done on your consistency, you will get there.
Hey all, I'm Sam from Wisconsin. I love drawing and I love friends. If you're in the Milwaukee area, I'm going to school for illustration and if you want to chat, feel free to send me a friendly message. I'm also on instagram as instagram.com/samguentherillustration and follow back! Also, if you have any cool procreate tips, I just got the app and I'm having fun with it!