It's a while since I had the courage to ride fixed (Good Friday, 2014 - look it up, if you CBA - or care less).
My fixed bikes (A Pomp, and an 80s Dawes conversion) were mostly silent and non-grumbly. I have no pretence at fettling skills, but what I found kept grumbliness to a minimum was:
a. 1/8th throughout. Just do it.
b. Work on getting a decent chainline.
c. Keep your chain taught. If you can't play it with a bow - it's not tight enough. Anything that looks like a washing line - well...
d. Use a gear that sits right between your sweetspot - which is a pseudo-mythical point between the cadence you can handle spinning downhill, and the "Almost a trackstand" point you can handle uphill.