Step one:
Chalk your cue
Step two:
I use the first OB as the CB and find my Pro1 or 90/90 shot solution to the second ball. I place my tip behind the 1st ball and point my cue down that shot solution line, just over an inch from the equator as if I'm eying it up (which is what a million other people do). Look at the cloth there to see if there's a burn mark, fuzz, chalk mark or some reference point. If not, there prob will be now since you chalked your cue earlier.
Step three:
Find a trace of chalk left by your tip on the cloth and fire away
Before people start saying that's cheating, golfers use intermediate targets all the time (blades of grass, spots of dirt, etc). Although it's illegal to use objects as aiming targets or to mark the rail or cloth, you can't help it if a spec of chalk falls off your tip while you're eying a shot. It's not illegal to place your tip behind a ball to sight a shot and you're not marking the cloth with intention or overtly marking an aiming reference. If a crumb of chalk falls, it is what it is.
Anyways, works for me.