Crochet - Granny Spike Stitch - leaves fewer gaps, because the second double crochet is crochet through the top of the second double crochet of the row below. Possibly use a dc,tc, dc pattern in the clusters? From Do It Darling.
Link for RANDOM STRIPE GENERATOR :)This is gorgeous afghan with random stripes, and it's all double crochet! A great beginner blanket or first project. There's a link to the random stripe generator in the post.