Ok, here's what I tell my kids, and anyone else who wants to learn to scrapbook, or rubber stamp/make cards... there are NO RULES!! I mean, what you think looks horrible, might be a piece of art to someone else, and vice versa. You are creating for YOU, and for your friends and family. If they are your friends, they are going to appreciate that you took the time to make them something and love you for it. Try out different styles. Try out new techniques. You'll find your niche' or at least have fun trying!
And, by all means, DON'T compare your art to anyone else's!! You will always fall short (because like you said, we are hardest on ourselves!)!