This post is a good roundup of free ribbons PSD and vector which you can use in your designs.These ribbon files would be a huge time saver in your timeline
Banners and Labels Sketches - Decorative Symbols Decorative
Hand Drawn Banners Royalty Free Stock Vector Art Illustration Use shading to add depth. Especially love the use of negative space on that one on the right, from bottom.
Illustrator Tutorials: 30 New Tuts to Learn Vector & Illustration Techniques