Need help with mastering a track

I recorded guitar for a song and it sounds pretty lo-fi… like it needs more treble or something. What can I do? I tried the Equalizer filter and it didn’t give me the results I wanted.

Any ideas would be appreciated.

If it is an acoustic guitar, use a better microphone and experiment with different microphone positions.
If it is an electric guitar, use a decent quality microphone to record the sound from your amp rather than plugging the guitar directly into your computer (or use an amp simulator such as a Line 6 Pod).

There is only so much that can be done to enhance a low quality recording. No amount of “tweaking” can put back into the recording sounds and frequencies that are not there.