Here are a few of the design 'exercises' I remember, from a class many years ago, that helped me to become less 'self-conscious' about my art and freed me up to enjoy it! It's essentially a 'playful' approach and if ever you are feeling 'stuck', a little bit of time doing some of these apparently pointless exercises could well lead you out of your 'stuckness'. I would even venture to say that, if you don't think of yourself as an 'artist' they have the potential to convince you otherwise!
1. Taking a line for a walk - literally just letting your pencil, or whatever you choose to draw with, wander about on the paper. Don't try to deliberately make 'interesting shapes' - in fact, don't try to do anything, just let whatever happens happen! I turned on the radio while I was doing this one and found my pencil moving to the rhythms of Beethoven's Violin Concerto!
If you find that you like some of the shapes you've made, you might like to add some colour and who knows? - you might even discover that you've made an abstract pattern that you can find a use for!
2. 'Ts' and 'Ls' Start with a good-sized piece of cheap paper - layout paper or even newsprint - and roughly mark out a grid on it in thick charcoal. (I think it's best to do these exercises standing at an easel but that's really up to you). Work as fast as you can - don't allow yourself more than about 15-20 minutes. And you may find that music, or television even, will help you to work more instinctively and less 'thoughtfully'.