Try blocking them all to the same size using pins, spray starch, and an iron. Sharon Schamber has some videos on Youtube about how to do this. Here are links to some of them:
http://www.youtube.com/watch?v=i6aplw_tVZc
http://www.youtube.com/watch?v=lIjZqABo2NY
http://www.youtube.com/watch?v=v-3RIWhBvcA
http://www.youtube.com/watch?v=sQkF02vpVuw