Excellent diagrams on circle-based patterns. Also a couple of good projects in which to apply them!
oval base for crochet bag or basket
sew by lovingjulia
Crochet Genuine Leather Bag - idea
코바늘가방 / 심플하고 예쁜 코바늘 가방도안 : 네이버 블로그
Mar y Sol crochet Tote bag
Bag crochet pattern