One more thing!
It might be helpful to expand by industry.
For example, when you want to set up clothesmaking, you need a relatively large number of people.
1st- you need pig tails, right? So you need a dedicated pig tail plot and a farmer to grow them.
2nd- you have to turn those pigtails into thread, which requires a farmer's workshop and another dwarf (this job should probably be combined with other plant processing jobs, like quarry bush work).
3rd- This thread must become cloth, so you need a weaver at a loom
4th- You want valuable clothes, right? Then you have to dye them pretty colors! So you need another famr plot growing dimple cups.
5th The dimple cups need to become dye, so you need a quern or millstone and another dwarf to work them.
6th - Dyer at a dyer's shop
7th - Finally, you need a clothier at a clothesmaker shop.
You then have 5 or 6 dwarfs busy most of the time.
If you still have lots of useless dwarves around, you can start another industry up. For example, butcher, tanner, leatherworker, bone carving, marksdwarves to shoot the bolts, a forge to make the crossbows, a smelter for the bars, miners to find the ore. See, everyone of those is a dwarf with a new job! There is always work to be done.