I prefer cotton underwear with no pantiliners, for all the reasons given by Owl above.
But some days I have a ton of discharge (been like that since I was a teenager, some really embarrassing moments at school); then, cotton underwear just isn't enough and I have to go with an unscented pantiliner for those days.
Otherwise, I don't do much other than shower regularly, because I do like my own smell (and so does my bf)
... I don't really think about keeping my privates clean when I'm at work, unless I'm on my period or something, since they know how to clean themselves.
I just make sure to wipe carefully after peeing and make sure there's no tissue stuck there. As for keeping pants smell-free... well, I guess I wash them in the laundry once a week, that's about it!
I don't think they get very "smelly" anyway, though.