I just love the banner pennant on the Celebrations cartridge. A plain-looking cut, and not so cute or exciting like other ones, but there's so much you can do. The simpler the cut, the more embellishments you can add, and you can get away with using wild patterned papers. You can join the pennants with brads, eyelets, or ribbons. The best thing about banners is that as long as you use brads or ribbons, the pennant folds up on top of each other making it easy to fit into mail envelope.
Here, I made a birthday pennant card for my sister's birthday, in her favorite pink tones: