This isn't really a party photo, I just love it. But, it comes from the blog Sew Sweet Stitches, which you need to visit just because it is so beautiful, but also to see THIS post which is are best instructions there could possibly be for how to make pom poms and simple paper flowers.
When my friends and I hosted a Senorita Party, six of us gathered at my house the week before with piles of tissue paper. We had the best time making flowers until late into the night. I could barely move in my apartment when we were finished. We had car loads of flowers. It was beautiful! We had the party at our church and the walls were brick, so there wasn't any problem putting the flowers up with tape.
When I have done this other times, like for Cinco de Mayo, I have used colorful serapes as tablecloths. If you have a large space that swallows color. This is a great theme to go with.