Losing men is normal? What, you want to keep your starting squad (assuming good rolls) stay alive they have the best stats. 95% of the problems people have in this thread with losing men is not scouting, and rushing into said unexplored terrain.
Designate one (or two) as your scout with the highest TU points, equip him with two shields one in each slot, a shotgun, pistol and 1-3 nades (you shouldn't need a lot of ammo at this point in the game even on insane, 1 clip is more then enough in most cases). You can drop the shield at the start and equip the pistol if you want, or just keep both on till one is used up (drop if less then <20).
-Use him first (best defense against reaction fire + shield to give him a fighting chance against any that do trigger)
- Keep the rest of the squad grouped and unexposed
- Do not rush
- Do not take pointless risks for a easy kill.
- Avoid night missions, crashed UFOs last a few hours, more then enough time for Day to sweep over it before you engage
tips to keep men alive on insane
- Always have enough TU to move back into safe cover 50% min, 100% or LOS cover is best
^*Take less accurate shots if you have too just conserve TU's to deal with surprises*^
- Do not leave units on the edge of corners
- Do not rush a lone alien unless you have scouted the area recently
- Grenades and high strength are your friends (always make sure units are encumbered a bit before each mission, more strength means kick-ass grenade throws)
P.s: Jackal armor is important on vet/insane iron man or not, build a few and give the first to your scout.
Two snipers, 1 heavy, 1 rocket, 3 riflemen and 1 scout is usually what I start with. Make sure every squadmate has at least 1 shotgun, 1 medkit, 1 stun, 1 frag. All grenades in the bottom slot, except for rocket/heavy place all ammo you need in those slots first, this will give you room for the shotty, medpack and 4 shots. If the soldier has a lot of strength fill with more grenades.
Congrats you now have 8 soldiers that can do short, long range and can throw grenades like Spartans (eventually), see what you need and change accordingly before you engage
posted on phone sorry NOTHING BUT BAD GRAMMAR FOR YOU TO ENJOY AND MAKE MIND HURT
EDIT: If you want to be lazy rush stun grenades, flash and stun is the quickest way to clear the inside of early UFO's in 1-2 turns
tl:dr Scout first, shoot second