Yep, I had this problem many times. I am right there with you about symmetrical planned forts. My solution(s):
- Build a temporary fortress at the soil layer. A dorm, a small meeting hall with kitchen and still, a catch-all stockpile, a workshop room, and a training room. Worry about metal armor an weapons later.
- Embark with at least three miners. Draft at least one migrant from each wave to add to the force. I am horribly nitpicky and reliant on miners to get an overall fort layout in place, including quantum storage and a big meeting hall, also elaborate bedrooms. The only shortcut here is to mine out soil layers first before designating any stone layers, since soil breaks up much quicker and your miners gain XP quicker.
- Embark with one military type dwarf. Give him odd jobs until you have some spare migrants to
sacrifice volunteer for a squad. Gather plants, make blocks at a mason workshop, whatever. You may wish to add a very cheap set of armor and a short sword (or axe, or hammer, etc) at embark if you can afford it. Use him to drive off any early annoyances. Alternately: a hunter. He will use his crossbow against enemies whereas a woodcutter will not use his axe.
- Wall yourself in early. Use blocks. Get a quick, fundamental wall built (with a roof) with any dwarves you're not using for mining. Make sure to remember to establish a trade depot and either wall it in too with a drawbridge, or place it outside the walls. Then you have time to concentrate on your fortress. Trade if you care to. After you're all established, you can always either tear down the existing walls, or build new stuff around it to enable surface farming, etc. Just remember to build a roof on everything, as dwarves will CLIMB now.
- Before the new version, I used a mod called Modest Mod which made regular training sessions much more valuable and worthwhile, eliminating the need for danger rooms (which are a pain, and pretty cheaty, IMO). Unknown if this mod works in 2014 versions, but if so I'll definitely be using it again. If I can avoid it I will always avoid using danger rooms. Big pain in the ass.
- Optionally, slap a training room on the surface. Military dwarves will need sunlight exposure anyway eventually or they will barf all over the place.
- GLASS. Use it and abuse it. It takes a little time to set up the industry but once you have a legendary glassmaker, you can churn out A TON of trap components with breakneck speed. Plain old green glass. Also good for doors (portals), chairs, tables, and POTS, which replace barrels and hold twice the volume while being lighter.
http://dwarffortresswiki.org/index.php/Pot I use glass exclusively for trap components, except for the occasional piece of goblinite I don't want to bother melting. If you're not familiar with the glass industry, definitely read up on it first. Tip: cancel any empty bags at embark, and instead buy sand. Any sand. Costs 1 point and comes with a free bag.
- Got a spare duck or turkey or something else non-grazing? Place it as bait in a goblin grinder:
http://dwarffortresswiki.org/index.php/v0.31:Trap_design Those things are effective.
Most of these tips I'm giving you presume you're not embarking on a hella dangerous piece of real estate. Evil biome? Get your ass underground ASAP and seal the entrance permanently, job #1.