I STARTED TO RIPPLE

I finally learned how to ripple after trying out a few different patterns that curled instead of ripple. I'm still at the swatch stage. The pattern that I found was for a pillow and the direction was to cast on 74 stitches and start at the 4th chain so my next challenge is do mulptiple of 74 or 71 because of the beginning 3 chains. Am I making any sense? I guess I just have to try it and check it out for myself.