INPUT:
You’ll want a flexible cast-on since seed stitch borders can flare. Try the long-tail or knitted cast-on, gently stretching stitches as you go. Avoid cast-ons that are too tight, like the backward loop method. Make sure to use a needle at least one size larger for your cast-on row; then switch to the correct size after. Take care—a stretchy start helps seed stitch lie flat.