For one mic a good starting point is pointing it at the 12th fret around 10 inches from the instrument. You can experiment with the position off/on axis of the microphone and also if you want to point it more to the thicker strings or the treble strings.
For eq, fullness is achieved around 150-240 Hz so you can search around there. I like a little 500 Hz in my sound but I cut a little from 3-400. Every acoustic is different though.
For a bigger presence, once you have a pretty good sounding acoustic you can try sending it to an aux and applying a small stereo chorus with a 20ms delay. It makes the acoustic even fuller and bigger in the fix. Then again if you have many instruments you need to round it out to make it fit in the mix.
Here are two articles you might enjoy.
7 reasons to love the acoustic guitar Audiotip a day. Mixing a great guitar Audiotip a day.