Pushpins on foamboard. Trace your design first, buy twice as many pins as you think you'll need. If framing, cut foam board to frame first. - Cute way to use the push pins I bought for my DIY headboard and didn't end up using.
Here's a fun little canvas I made using some of the new Doiley rub-ons. It's really easy to make, and you only need a few supplies; Doilies Rub-ons Blank Canvas (mine is x Decoupage First cut out some.