A nice pair…
Many of my favourite recordings were realised with just a single stereo pair of microphones. If one has an acoustic appropriate to the music being performed, this low-key setup is almost always all that is required. (And even in multi-mic recordings it is the humble main pair which tends account for 90% of the mix.)

While such an approach is not always possible—or even desirable—given the right set of circumstances, the results can be astonishing. Have a listen to the playlist below. Everything you hear there I recorded direct to 2-track recorder with only a single stereo pair. When the minimal approach works, it really works.
psappha-mackey-microconiv.mp3amanda-thesoundsofrain.mp3philharmonia-scotland.mp3konrad-4040test.mp3owduo-rikyu.mp3albaquartet.mp3euan-loch-lomond.mp3suppertime.mp3In essence, there's little more to it than finding just the right spot to place the performer(s) and then just the right spot to place the mics. You know you've found it when suddenly everything converges: the tone of the instrument/ensemble is right, the stereo image is strong, and the balance of direct-to-reverberant sound is conducive to the repertoire. Sounds easy, but it's rarely a task without a certain degree of challenge.
Once the mics are set up, the session proper can begin. The format varies from situation to situation, performer to performer, but I generally favour a hands-off approach with all focus on cultivating a relaxed atmosphere and capturing a captivating performance. I try to keep takes long and not to get bogged down in too much patching, saving that for only the most difficult spots. I find that if a session gets too patchy, the music almost always suffers.
Of particular interest to the classical bods among you: I'm a fluent sight-reader and very comfortable working with scores during a session.