Very quickly...me sleepy...

verbal spotting - Keep it very short. Take too long and the information is of no use because the whole squad is dead. Which direction (be aware of your North, South, East, and West at all times, don't do it relative to your screen, your left is someone else's right.) how many (whole squad, lone wolf, a few soldiers), armour/infantry and if they are higher or lower than eye-level if this is applicable to the situation.

E.g. "Contacts East, probably a full infantry squad, up high on the bridge"

Verbal requesting/suggesting - Question and suggest orders if you think they might be wrong. Don't be pushy, and remember to say I told you so if you were right. Do not stop and halt squad's progress, just to question orders, and do not over-question and be annoying.

rule: when SL talks then be quite - Erm...pretty much.

Stick with squad - See Lorax's and Eroak's post for info. on spacing. Other than that, yh, stick with the squad, don't leave your squad unless ordered to, which will be rare.

revive often - See Revival SOP for more info.
q-spot often - See Spotting SOP.
get on the flag when capping - The more bodies the faster it flips, meaning backup can spawn at flag and enemies can stop spawning on flag. Do not group up on flags, consider spacing techniques suggested by Eroak and Lorax. Also may want to conside sending one or 2 back from flag in safe area as a contingency for reviving or contining capping if those on the flag go down. Make sure your SL is one of the few staying back so you can spawn on them if you go down.
move with the squads - Yuhha.
LISTEN CAREFULLY - DO NOT GET TOO ENGROSSED IN TAKING POTSHOTS THAT YOU STOP LISTENING TO YOUR SQUADLEAD. Every order they gives you is for a reason, even if it is not immediately apparent. Hold spawn when told, spawn in when told, take correct kits. Following orders is the first step in understanding strategies and tactics.