The following blog post is going to cover a range of different acoustic and electric guitar production techniques suggested by a variety of recording/mixing engineers.
Acoustic Guitar
Graham Cochrane, the brains behind TheRecordingRevolution.com, is a recording engineer that has came to fruition due to his valuable knowledge around the recording and mixing process. In a video he made pertaining recording the performance of an acoustic guitar, he discussed the varying ways a microphone can be placed in front of a guitar so to capture its sound in the way you intended. He suggests by backing the microphone away from the acoustic guitar to around 1 foot and aiming the microphone around the 12th fret, you’ll capture an even frequency response of the guitar, meaning the low end frequency content isn’t going to have to be reduced via EQ and the but also there is enough higher frequency content to ensure the guitar doesn’t sound too dull. However, he does state that it’s about understanding how the guitar fits within the framework of the song [0:10-2:55]; an overly thin-sounding guitar might be perfect as a “texture piece” – working alongside a variety of other musical instances – it just depends what you feel the song is requesting from the musical instruments
He also is using a large diaphragm condenser microphone (LDC) microphone.
Electric Guitar
http://www.soundonsound.com/techniques/guitar-amp-recording
References
RecordingRevolution (2016) Recording Acoustic Guitar (My Foolproof Method) – TheRecordingRevolution.com. [online video] YouTube. Available from https://www.youtube.com/watch?v=cZRnrA5GOx0 [Accessed 16 March 2017].