Was a bit surprised something like this doesn't already exist. A very basic jig to mark 3 ¼ inch golf tees with a line at 1 ½ inches. 1 ½ is where I find works best for my swing, and is generally a popular tee height. 

Unfortunately the tees with lines already on them are wildly inconsistent in heights and every little bit helps in my experience. The hole for the tee should accommodate just about any standard or wood tee. The hole for the marker is large enough to fit a regular sized sharpie. 

I personally used some double sided tape to tape down the jig, that way I can just place the tee in the hole and spin it to mark it. 

Printed it in Prusament PETG as that's what was in my AMS, but any material should work fine. Probably a good idea to use a brim as well.