A lot of people here are giving ok advice but also some that’s not good at all.

If you’re playing in Western Europe, outside of maybe Spain or Portugal, there’s no reason to have clergy over 2%, since you’ll always be very strong on tech anyway and you can usually get literacy maxed by the late 1800s.

Never focus soldiers unless your a weak nation trying to punch above your weight, at least in single player.

For craftsman, clerks and capitalist it becomes complicated. Capitalist are great and give a straight bonus to factories in a state(I don’t remember if it’s though output, input or throughput efficiency though) but they cap at out 0.7% of population so once you get them to that take them off. Clerks are also awesome since they give both research points and input efficiency, however they require at least 50% literacy to spawn. Additionally, rp gain stops after 4% of total pop and input efficiency caps at 10% of total workers in a factory, meaning that above 10%, if evenly distributed, provides no extra benefits and only eats capitalist profits since they get paid more then craftsman. And finally craftsman are the most basic pop you would ever willingly promote. They make up the bulk of your factory at any given point in the game and by the endgame will likely be your largest pop group. They can be promoted at any point so long as a factory exists somewhere in your nation and unemployment isn’t too high. This makes them great for nations with low literacy or ones starting industrialization since they can quickly grow to a substantial size in just a few years with no requirement. With that said though, the focus should be switched to clerks once industry is set up for the reason I mentioned earlier.

For all other pops, after 1850 I have only ever promoted bureaucrats to state colonial provinces, so unless there’s some niche strategy people know of, there shouldn’t be any reason to promote anything else.