I do this all the time, we call it milk wash, it is the going thing in the new homes here. All I do is take some white oil based paint mix it about half with paint thinner (test on scrap, to see if you like it)use a GOOD oil brush. Lightly dip brush in the mixture and tap on sides of can to remove excess, brush it on evenly, being sure to leave no runs or holidays (missed spots)and leave it be. The next day I spray one coat of laquer sanding sealer, sand with 220 grit being carefull not to "burn" the edges, matched putty, blow or tack off dust and two coats of laquer.
You may use the clear coats of your choice besides laquer, just be sure to sand and tact off the dust between coats.