I agree with Tenderfoot's teachings.
And all dogs are different.
For ours it's practice and exercise. Exercise is a biggie. If we've neglected to take our dog for a 30min run with us, or a long hike at least 2-3 times a week, she's a lot more difficult to handle.
Our dog gets riled up when we pass barking dogs behind fences. A 'treatment' I've found for this is to give your dog a command that they know really well (in our case, the "sit"). When we approach these 'hot spots', I keep her on a short least, with me in front (or between her and the 'offender'-hopefully so she knows that I'M the "protector", not her). When I can see her start getting riled up, I say the command, treat right away for positive response, then move on, ignoring the 'offender'. I find that this has helped her to keep her attention on me, and not loose her mind with the other dog. Sometimes it takes a couple 'sit' commands to be on our way. She started to remember this and has been a lot more responsive when we pass those 'hot spots'.
I was wondering if you could tailor this for face-to-face encounters? (Our girl isn't really bothered by the face-to-face encounters. And I guess that you'd have to have a command that you and your dog are VERY comfortable/good at (reference Tenderfoot's post). Hope that's helpful to you!