This is my general cactus mix for my potted columnar cacti. I adjust mix accordingly depending on the cactus' native habitat. Desert cacti get more pumice and sand, while cacti that grow in forests along with many trees would get more loamy topsoil.
For in-ground mix, I will use this mix along with native soil. I adjust more sand, pumice, and native soil depending on the type of native soil and how it drains.