One of the most overlooked items during recording is placement in the recording room. Most times, placement of the instrument will be either random or whatever's convenient, but it plays a big role in how your recording will sound since the environment is so much of the total sonic package.
Here's a excerpt from The Drum Recording Handbook regarding placement. It's obviously about placing the drums in the room, but the techniques apply to other instruments as well.
"If you do nothing else, positioning your kit in the best acoustic place in the room will do wonders for the sound. What you’re looking for is a spot where the drums or acoustic instrument sounds relatively live without any of the room cancellations. Try these following steps to find the best room placement:
1) It’s usually best to stay out of a corner. The corner normally causes “bass loading”, meaning that the low frequencies will be increased causing your kick and floor tom to be louder than the other drums. This can also lead to increased ringing and snare buzzing. That being said, don’t rule the corner out without trying it first since the extra fullness of the kick might be just the thing you’re looking for.
2) Pro engineers will usually test a room by walking around and clapping their hands. That’s a good way to find a place in the room that’s has a nice even reverb decay. If the clap has a “boing” to it (a funny overtone), then so will your drums so it’s best to try another place in the room.
3) Ideally, you don’t want to be too close to a wall. The reflections (or absorption if the wall is soft) can change the sound of the kit. The middle of the room usually works best.
4) Ideally, you want the place in the room with the ceiling height is the highest. If the ceiling is vaulted, try placing your drums or acoustic instrument in the middle of the vault first, then move as needed.
5) Whatever you do, stay away from glass if you can. Glass will give you the most unwanted reflections of just about any material. If you have no choice because of the way the room or the band is situated, try setting up the kit at a 45° angle to the glass."For some additional excerpts from The Drum Recording Handbook and a look at the table of contents, check out the Bobby Owsinski website.