I begin by digging out an entry tunnel and ramps spiraling down to stone. Once there I dig out a few large rooms that can later be re-purposed into work areas, and they form my initial dorms. My starting seven are always unskilled peasants, and the extra points go to additional supplies. I tend to be very minimal: just some meat, drinks, seeds, a couple ropes, some livestock (including guard dogs), and all the copper and tin ore, wood, and fuel I can carry. Typically three become miners, two become carpenters and woodcutters, one becomes a mason and one gets all metal and smelting jobs enabled. The miners dig, the woodcutters cut, and the mason and the smelter soon get busy making metal, chairs, tables, and blocks. A few beds get banged out after the first tree drops, but that's all initially.
With the new jumping and climbing mechanics, I now dig a trench several squares wide and deep to isolate a patch of surface land for agriculture and pasturing, then assign my woodcutter and any bored/idle dwarves to help throw together a wooden wall around the perimeter. Before I'd just channel and remove the ramps to make a temporary plateau to thwart enemy shooters, but the world's a scarier place now.
My entrance has a regular bridge (to seal the tunnel) followed by a retracting bridge that, when hidden, reveals a dip that includes a number of traps (the bridge covers them so that wagons can share the same route).
Initially I dig out work areas for agriculture, then get that stuff rolling. Next is expanding the stone-layer work areas into a proper industry level, and making a new, larger dorm area with a decent dining hall and a couple offices for my manager and bookkeeper. After that comes military (by now there's usually enough migrants and bronze bars for at least a squad of 5), and then a catacombs, jail, and hospital. Lastly I start adding private quarters levels and planning for deeper expansion.
This whole process is a bit tedious, but by the middle of the second year it's usually starting to run smoothly (enough bodies, workspaces, and resources to keep things humming along). I try to trade as LITTLE as possible to keep invaders to a minimum until my military is up and running (I use minimal traps since they're overpowered imo at the moment). By the third year my forts typically have plenty of food and drink (and plenty of variety), enough thread between plants and shearable animals to sustain the need for new clothes (though my starting dwarves tend to be in tattered rags by the time the first fresh pants and tunics come), and enough industrial work to begin serious trade.
I don't tend to get much further than this at the moment; I've been holding off more ambitious plans until the newest version gets more fleshed out and stable, as I'm quite excited to build up an entire dwarf civ via retiring and expanding. For now it's just tweaking those initial years and then trying out various alternate expansion plans. The biggest hurdle for me is the military: I'm slow to build it up, and I don't use danger rooms (see my thoughts on overpowered elements above), so those combine to leave me woefully under-defended when danger does come calling.
With climbing and such now a reality it's shaking up my process; I lost a fort recently that I didn't realize had a tower near the embark. An army of 30+ undead arrived, lept over my apparently too-narrow ditch, climbed the walls, and poured into my fortress from the pastures.