Keep your old works. I really like to draw portraits, and I have been learning to draw portraits for three years already. Now my pictures looks well and people who I was drawing in this pictures, looks like themselves. When I was younger, I felt embarrassment for my old portraits because I thought that it's nightmare. I didn't like my first works and I had burnt it. (I mean, in fireplace) Now I regret that I don't have this portraits, because I want to see my first picture. I want to see progress between first portait and last. So, if you don't like what you do, try to do better, but KEEP YOUR OLD WORKS.