Wow, and my Classic Ironman run is finished - after 92 days. I lost too many troops, and had to keep sending out rookies - to die. Even with carapace armor & laser rifles. I think the pacing on Classic is too fast, from that run - I was getting hit by Mutons just after the first (only) terror mission I had, and everything was hitting often & hard.
I know I made a couple of mistakes early, moving in too fast or leaving troops without enough cover. The aliens were definitely moving to flank my guys, which resulted in me taking a lot of hits. Plus, the constant lack of funding early on is pretty harsh. I almost think they didn't balance the funding well enough - everyone should give you some token money, if they're part of the council, and then more as you put up satellites.
What priorities do you folks go with, on Classic? I started in Asia (and never used the perk), focused on Engineers & cash rewards early on.
My successful run was in South America. The reason was that you need a really successful start to succeed on classic iron man or you're completely boned. So everything I did was to maximize that.
I would take 2 rookies on every mission. Get as many squaddies as I could. All the way till I got the OTS second final level thing where everyone would be a squaddie. This way if anyone dies I still have useful soldiers instead of a handful of crappy morons with no skills.
I rushed to laser weapons before all else. So that means capturing a sectoid for the boost. Getting two labs, etc. I'm not sure how to optimize that but that's what I went for. My rookie survivability rate went through the roof the moment I got those.
I never bothered with Shivs. They died too easily and couldn't take cover. Good distractions though, but really expensive for just a distraction.
Then just try to do very well in missions I suppose, though I guess that should come naturally. Be super duper cautious. Never use shotguns, since you'll end up dying. Never go close range, since you'll end up dying. Proceed at a snail's pace and use hunker down liberally. If you think the enemy has a good chance of shooting you, grenade him or smoke yourself. Even if it's just a shitty sectoid. If you see an enemy and the probability of success is lower than 60%... hunker down. If you see an enemy and he can see you, don't overwatch. Hunker down. Never risk it. Ever. That's the hardest thing to overcome. You'll need to do that to stand a chance of success. It's really boring, but that's how careful you have to be. Once you get super armour and your units can survive more than two shots then you can be a bit more relaxed.
Oh yeah, I think the most important skill I learnt was running away. See a new alien group? Everyone run the fuck away back to spawn! Run run run! My guy got critted and he's at 3 hp? Run the fuck awaaaaaaaaaaaay!
But really, it's all about getting a great start and levelling as many guys as possible. It normally took me about an hour just to finish one mission when I started. Hope that helps.
Tl;dr:
1. Get as many levels on as many soldiers as you can. If you run out of squaddies it's game over.
2. Get better guns.
3. Take forever to do a mission. Always be cautious. Never take risks.