Shoot mostly with a shallow DoF unless there's a beautiful background like that sunset in your sig.
posing is pretty much anything couple facing you, away different angles, keep them especially heads close all the time not further than an arms length away (i know sounds weird)
what i find most important even with friends...keep CHATTING with them not just telling them how to pose, this keeps them at ease and when they're at ease posing comes natural.
*note* not a pro, i shoot a lot of crap (PPG shoots me down a lot) but i do get the odd shot or two that really impresses even me