when i do them as a general rule:
clean the fac eof the tube and the bezel glass that right there usually makes a huge difference.
Then i power on and warm it up, first things first set focus. Just tur that pot back and fourth untill you get it dead nuts on. Then set coarse brightness high untill the raster lines appear, then dial back till theyre just gone, and then dial back just a touch more.
After that i adjust the colors is needed. Turn up each pot untill that color bleeds through, then just back down untill the color stops bleeding. You may have to go through these several times before you get it perfect. When your done with that if you have too much or not enough of a color, you know what to do.
Then you can move onto small stuff like picture size, contrast (and im some cases) black level, etc. If atany point now you start getting color bleeding, go back and readjust your color pots again
Its not too hard man.
also a proper mirror MAKES ALL THE DIFFERENCE.
check out the first minuite or so of this vid and you can see what i made. You dont have to get that elaborate but you get the idea.