Advanced patterns expect comfort with most crochet techniques: complex cables, lace repeats, tapestry/intarsia colour-work, and precise shaping. They reward careful counting and a willingness to swatch — gauge mismatches compound quickly across a garment or a large blanket.
For the trickiest sections, work a small swatch of the technique in scrap yarn before committing. A 30-minute swatch saves hours of frogging.