Hi, How do make yoga mat alignment marks?

Hi, How do make yoga mat alignment marks?

no commercial pre marked mats, prefer to do it by myself

On a plain yoga mat I question if my hands and feet are in the right place, or wonder if my stance is too short or too wide in certain poses.

Checking if there is mathematical* calculation in proportion of my body size to make marks on the yoga plain mat and follow those lines and marks that help keep the body in the correct alignment and position when practicing,

Hello Kxandra,

Every body is different, some have longer limbs compared to the torso and vice versa therefore there is no universal one size fits all mathematical formulation for alignment.
My advice would be to grab a ruler and mark a center line. Then mark a horizontal line where your hands should go (like a starting line for you fingers). Then from the center of this starting line for your hands you should mark a vertical line (length of mat) where Your feet should go in positions like down dog. The reason for a vertical mark for your feet is as you progress and open up your feet will move either further back or forward (depending on the asana) whereas your hands will almost always start in the same position.
Another idea is to mark it like a grid. My black mat pro has a grid texture that helps with this. Hope this helps.