Well in 9 ball the pattern is pretty clear-cut

You just always play at least 3 balls ahead and you should get out, though sometimes additional planning ahead is necessary (nudging a cluster for example).
In 8 and straight, I tend to group balls into "buddies"... happy pairs or threesomes where playing one shot gets easy position on another with a simple stop shot or very minimal cueball movement. My mental process might sound something like this...
"get the three guys at the head of the table"
"do them in this order rather than that order so that when I shoot the third ball I get easy shape on the rail cut"
"the rail cut is a stop shot to shoot this other ball directly in the side"
"from the side pocket shot I can get on the other 2 balls, the second of which is a rail cut that is basically a stop shot for the 8"
That pattern in particular comes up a lot. I very often find myself working from the top of the table down to the racking area in 8-ball. Maybe that's just me.
For straight pool, there are some conventions that center around "solve your problems first". The pattern is dictated by the problems. So your first priority is breaking open the rack or large clusters in the rack area. Then your next priority is opening up any remaining clusters, then taking out balls that block other balls from going, then getting balls off the rail... and by the time you solve all those problems you'll be lucky if you have 4-5 balls left. In which case the sensible approach is to just work backwards, or stare at them until you see a series of shots that can't possibly be screwed up.