1. Hand won’t cooperate - When you have the idea, but when you try to put it down the quality is far less than what you are capable of.
Usually for me this is because of something messing with my cognitive function, which is almost always sleep. But sometimes it can be not enough food, or coffee, or something that gave you an adrenalin rush. I recommend self care. Laying in bed even when you can’t sleep, getting a bath before bed, messaging your hands, playing your favorite music, stretch, go on a walk - Do whatever you need to do to take care of yourself. Self care is very important to your wellbeing.
2. Scrambled - You have a vague idea of what you want to draw. Unfortunately, each time you try to draw the image, it keeps shifting. Nothing fits together like it usually does and the drawing looks scrambled.
Because what you want to draw is so vague, you get drowned in too many ideas about what you want to draw. I recommend writing out what it is exactly you want to draw. You can also sit in a quiet space and try to bring up the image in your head. Try to grasp every detail that you want to draw and write it down. If you can’t quite gather the details of what you want to draw, it might be time to rest for a bit before trying again.
3. Empty - Empty of ideas. You stare at the blank page for an hour before giving up. The classic art block.
Doodle. Draw eyes, hands, faces, whatever. Just doodle. It doesn’t even need to be a shape, or an object, or something alive, just draw lines or gradients. Fill an entire page.