Many years ago when I was studying conducting with Frank Battisti, I asked him if there was any one skill an ensemble player needs that stands out above all others. Without a moment’s hesitation, he responded, “An exquisite sense of tempo and rhythm.”

I strongly urge using a metronome for much of every single practice session. A lot of us think only people “with rhythm problems” need to use a metronome, but when I used to walk down the halls outside the Coast Guard Band practice rooms, I would always hear metronomes clicking in the rooms of the best players. Enough said?

For some more ideas on the subject, check out
this site. Don't let the youth-oriented appearance scare you off—there's a lot of good sense here for all of us. I particularly recommend "Part I - The Five Steps of Practice" for some ideas on how to effectively work the metronome into your practice routine.