7 Free Top-Down Raglan Crochet Cardigan Patterns (No Seaming Stress!)
Here's a secret that changed everything for me: you don't have to sew your cardigan together when you're done...
Free Crochet Patterns & Video Tutorials

Free crochet cardigan patterns: granny square cardigans, cropped styles, long dusters, hooded cardigans and simple everyday layers.
The granny square cardigan is the one most people want to make, and it is genuinely easier than it looks. It is usually built from a small number of large squares joined at the shoulders and sides, so there is no complicated shaping at all.
Whatever style you choose, swatch first. Cardigans hang from the shoulders, so any gauge error multiplies down the whole body. See also granny square patterns, sweaters and all clothing.