What do you guys do for squad selection strategy? Depending on the difficulty of the mission I like to send between 1 and 3 low level guys on every mission. This provides 2 benefits. One I have a steady flow of guys leveling up, and two it provides me some fodder to use as scouts while my vets stay further back in support. If I lose a rookie oh well, for $10 I'll have a new one on the way, but if he makes it through he's usually got a kill or two and a promotion on the way. It also helps ensure that if my squad does get wiped out that I only lose a couple of my more advanced soldiers.
What do you guys think?
In the beginning I like to lvl up my squaddies evenly, so that there's a better chance that one of your desired guys can be a psy soldier later. You can swap out armor easily enough and it automatically unequips the gear too.
In the beginning I like to get snipers leveled up fast so they get squad sight. Then the composition of:
1 assault, 2 heavies, 1 support and 2 snipers.
Heavies with bullet storm and suppression + rockets, assault to flush and run-gun and snipers to pick off anything anybody sees. Support does scouting or healing, one or the other. On some city maps or big alien landings I'll bring 2 supports or 2 assaults, the 2nd heavy is often interchangeable depending on your squad rotation.
Later on you need all veterans, rookies/squaddies can't hit jack diddily squat even with a scope and a LPR.