There is a thread about this in another section of the forum, but it's always good to talk about it in here I suppose.
What do you want from Squad Leading? If it's to spot for a CAS squad, to lead an Inf squad, or to take some guys across the map to build ninja-fob's, you're objectives from the game are different and you'll need seperate advice for each.
Personally, when I lead an Inf squad, I just try to get into the thick of it with as little walking as possible.
My 'objective' is to have a good firefight, and help my 5 guys overwhelm the other guys' 5 guys.
Seeing as I accept this is why I'm leading, it becomes a bit simpler! Generally I don't mind what kits everyone takes (as long as there's a medic if we are over 3 players). I see HAT, LAT and AA kits as defensive (to be requested only if fired upon from beyond the range of everyone elses guns, and I treat the main strength of my squad as the ability to fire 6 guns at (hopefully) one enemy at a time (#laughs madly#).
That's the theory anyway

I do tend to tell everyone that I want to find and kill the enemy (not wait for them for 30mins), and people seem to still stay around me. And we do tend to have a few good moments, although depressingly I find nowadays that I'm a bit lazy and just garrison the nearest building to the enemy. But to be fair that's how you get by.. You play defensively, offensively, unfortunately.
To be honest, I could do with playing a bit more, I'm not as good as I used to be at squad leading.. Lol.
PS. Taking to other squad leaders. This used to be a bit of an art, however since nobody extra can hear you now, and only half the guys you talk to bother to reply, you can basically be as lax as you want. Although I do try to be serious sometimes it's just easier to be really colloquial, and not really convey that much info but waffle on a bit. Hey, at least I admit it. And at least I initiate it.