f the acoustic guitar forms the primary rhythmic and tonal structure of your track, small amounts of compression will help it gel with the rest of your mix.
Set the ratio between 3:1 and 8:1 and then adjust the threshold to catch only the louder peaks (somewhere around -6.0dB should do it). Then, apply a fast attack to blend into the mix or a slower attack to highlight the attack of the pick. Adjust the release time to a fast setting to control transients or to a long release for more overall gain control. Below is an example from Logic Pro.