I've always wanted to do a gig poster and I finally got to do one. I did mines for Toro Y Moi. I had struggled with the piece mainly with the decision of what kind of palette to use. I went through many palettes and hated most of them. But finally I just followed my instinct and used complements red & green and went from there.
If I would change anything is add a bigger bleed space. I think at one time my bleed space was fine, but then I had to move the "Toro y Moi" text around and make it bigger so it wouldn't bump up next to the trees behind it. I would also do better hand type at the bottom. It's not terrible but it does bother me a bit. It just could have been done a bit better. Overall I'm happy with my gig poster, I think it came out great.