I pick 2 of my starting dwarfs to be dedicated soldiers. I build a carpenter shop and immediately build training axes, shields, and a cabinet and set them to train forever (replace the training weapons with real weapons before they become attached). I build the barracks in a place on the surface near my entrance where I expect enemies (gobs and wildlife) will come through (in case an ambush is too close to react to, its probable that the military will be the first to see them and already be in position. No orders needed.)
I refuse to build inaccessible forts and don't use traps.
Sometimes the crossbows gobs shoot them down and I lose. Sometimes, one will single-handedly repel and chase down several squads. Sometimes necromancers resurrect hairballs and severed thumbs until they are overwhelmed and hoofed in the head. Most likely, they will see a fisher get gobbed in the head, sulk a few weeks and then throw a fit and axe half the fort in the head while the other half breaks the dining room until I rage quit.
I don't take things that I can easily make myself like ropes, thread, buckets, or axes. Instead I take raw materials like wood, bituminous coal, copper bismuth and tin ores, one refined coal (so I can skip the whole wood burning thing), a few stones ( just in case I can't get stones immediately) extra food and drink and sometimes a pair of egg layers. Bronze is CHEAP and better than copper, which is the most likely thing gobs will swing.
Later I split the 2 starters into 2 squads and add 2 recruits to each squad. when the recruits get around talented, I move them both to squad 3 and add 2 fresh recruits to the first squads. And repeat until I'm satisfied. If any recruit becomes legendary enough they get to start training recruits like the starters. Eventually I'll add turrets to the above ground and train 5-20 crossbow dwarfs depending on population. If I get bored, I'll cross train the melee troops to dual wield axes and bows (which I think is a bad idea, but it's cool.) or something else Fun provoking.