A regular person can sew normally on Chol Hamoed if it is necessary. A craftsman can only sew with not normal stitches.

Interlacing a bed, when beds were made of a spring of laced string, is permitted on Chol Hamoed. R’ Yosee says you can even tighten these strings.

Moed Katan 1:9

In times of chazal ovens were circular earthenware moveable items.

You can set up an oven, which means attaching it to the ground with mud, on Chol Hamoed.

R’ Yehuda says you cannot roughen a new milestone on Chol Hamoed as it is the work of a craftsman.