This is a great subject. I always get bored with the slow FPSs as my fortresses go into late game, so I've never had, for instance, a really strong metal industry. I think next time around I will assign a greater percentage to smeltering.
I currently have a population around 100, and I think I might actually cap it, since I can't see gaining much useful from more dwarves standing around. Maybe double up on crafting, but I'm already sending away caravans empty of their metal, cloth, and leather, with thousands of dwarfbucks in offerings, and 50% profit, but am still designating new stock piles to store all the extra crap I'm making.
My oldest general goods stock pile has about 4x31 bins in it, all full, along with the other 27 rows of the stockpile.
I try to keep around 20–30% in the military. This, and the percentage of my population assigned to haul and idle goes up as the population goes up, because the need for things like crafters doesn't grow linearly with population.
I have five dwarves that sit idle with nothing enabled but the medical skills. Before I hit 80 or so they hauled too, and just got pulled off that in the rare case of injury. So far though my dwarves have mostly returned from battle either uninjured or dead, so they don't do much.
I always start out with 2 miners, and then add a couple more once I'm over 30 population or so, up to around 5, but in my current game I'm experimenting with only two legendary ones. It's working alright, which is kind of funny, because now with burrows we actually have the ability to make sure it's the beginners that're mining tree farms and storage rooms, and the masters that are extracting ore and gems.
As my population grow and I get the main structures all carved out, and farming finally stabilizes, I get more and more producers going full time. Though my mason and stone crafter are going from early on. I never bring a trained stone crafter, but almost always turn someone from my second military wave into one.
I aim to have two stone crafters, one or two bone, and one each leatherworker and clothier churning out trade goods and new clothes (for satisfying acquisitions).
I add one dyer, and right now the farming industry can't keep up with him.
I always get a map with sand because I love the glass industry. I do feel kinda cheap making terrariums as cages, so I'm hoping for cage strength calculations soon.
So I have four right now, and may add a couple more as time goes on.
I don't start with jewelry until I've got a stable-ish glass industry to help train them, and generally go one each, but sometimes add a second setter to keep up with the cutter.
If you have no glass industry constantly making gems, you may want to combine jewelry onto one dwarf.
I have two workshop assigned masons and two engravers. Normally I wouldn't even have the second mason, but he arrived with High Master in the skill.
I also have a couple masons not assigned workshops that do constructions around the house. Once I start building towers and above ground obsidian casting molds, I'll add more.
I only have one of each metal class. Any backups with the right skill are just doing something else in the meantime. I imagine I might add another metal crafter, and possibly another blacksmith if I decide to, say, give absolutely everyone metal furniture. I definitely only have one full time armorer and one full-time weaponsmith, training up towards legendary. Once I have a full set of masterwork armor, weapons, and traps, they can basically retire.
I do endeavor to avoid giving any extra moodable skills to migrants who have metal labors, so that a mood might give me a boost.
I have the custom label "tender" on about six dwarves right now. Each of these dwarves has all non-quality farming jobs assigned (milker, thresher, miller, etc), no other non-healthcare/cleaning labors. Considering making them my construction masons too.
I might separate out wood burner and asher, to supply my glass industry once my tree farms have matured. I'd also say to fertilize the farms, but I'm already producing more vegetation than I need.
I use the custom label "porter", on about 15–20% of my population.
Each dwarf with this labor has all hauling labors assigned, wood cutting and weaving. One (or more) loom(s) would be assigned to only porters, and another would be assigned to only my actual weaver. The first had "collect webs" active, the second the actual weaving jobs on repeat.
I do the same thing with glass furnaces (though of course, I don't need to turn on the glass labor for hauling sand bags).
The biggest aggravation with this methodology is that I can't use the manager for weaving or glass assignment, since if a "collect ..." job gets canceled, that can choke up production.
In 40d, they'd also be my masons, architects, and engravers, to get those stat ups that the exp would provide. If they seemed very social a couple would occasionally get year long vacations to chat about whatever, and get social exp.
They were also pump operators, and that still applies to my .31 forts.