1. Create dummy squads / reserved squad positions for the real army.
Why? it's easier to manage regular army than civilian army.
For a population of 120, do I want all my civilians in the regular army? or say perhaps 2/3 of them = 80, or maybe even 100 army, 20 civilians/nobles?
Why is this an issue? It's when I press "s" to order a squad, the first 10 squads from a to j are selected.
I find it convenient to have the first 5 or 6 are my melee army, then 7 to 10 crossbows, and the civilians will be the 11th+ army.
Also, equipment upgrades availability trickle via squad position from 1. I want my first batch of candy armors and weapons to go to the real army first.
2. Schedule.
Winter season is a good time to stop farming, brewing, chopping trees, gathering herbs, hunting, and even mining.
Set schedule for the civilian squads to train on the last 3 months of the year.
If you use DTherapist, you can utilize the "custom professions". Make some for your civilians, and make one for military in training. It would then be simple to sort by squad and set toggle professions when the game pauses with "Winter has arrived."
3. Perfectionist trap
I often find myself delaying of making the civilian squads to start training because I am waiting for weapons or armor. I learned that I should not wait on equipment because they can still learn about other aspects of fighting: dodger, wrestling, kicking, observer, discipline.
4. Min/Max trap
Oh there are different ways to go about training a dwarf. Sure I can start with no weapons and no armor and start training in a barracks. But some skill progress are worth noting.
A rookie equipped with shield + armor, the block skill will gain more and leave behind armor user. So it is worth considering to delay giving shield so that armor user skill go up faster. The benefits of high armor user is wearing heavier armor such as copper has little effect for a legendary armor user in terms of movement and number of attacks (well, and weapon skills for number of attacks).
Other than that, not exact science, but it seems that having higher weapon skill increases the likelihood to sparring. Sparring is the goal to increase the speed of level up of skills via training. So it is worth giving them even wooden training weapons for those civilian squads.