well, I should define my idea of "basics", first - it focuses on thrift store trawling and adapting commercially-made garments.

I think going-beyond-the-basics would get into alterations to patterns for common costumes, dyeing fabrics (including hard-to-dye ones), creating embellishments, that sort of thing.

My idea of cosplay-101 assumes the cosplayer can't/won't sew.