Don't get rid of old artwork.
You know, that pile of work from high-school or college or (insert time period) when you first felt like you were a "good artist"? The stuff that may or may not cause you to cringe at the sight of it?
While organizing piles and piles of artwork and supplies this afternoon, I stumbled upon lots of old drawings. Some which I had forgotten even existed. And yes, some of which made me laugh at my younger self a little.
No, I'm not going to post any. Good try, though.
Do you know what's great about all this past art? No matter how I happen to be feeling about myself as an artist today, or next year, or whenever... I can always pull out these drawings and paintings and be reminded that hey, I've come a long way. My skills have improved even when I didn't think they had.
I don't know if this is more true for younger artists than it is for experienced ones. But my guess is that we as artists, illustrators, or designers will never stop learning and improving.
So, are you in need of a little affirmation as an artist today? Go pull out that dusty old sketchbook or project from three years ago and smile in satisfaction!