Microphone Techniques
Let's look at some simplified mic placement or signal input suggestions.

Acoustic Guitar

Use your condenser mice for increased presence. Use your dynamic mic for fuller bottom end.

1. Point the front of the mic toward the middle of the sound hole for more bottom or point it toward the neck side of the hole for a bit more highs.

2. For a more live sound, have one mic (the dynamic) near the hole about 10" away and have the condenser about 12 feet away IF you are in a very quiet room. This will give you a bit of natural reverberation.
   
   Studio Tip: Sound travels about 1 foot per millisecond. So if a mic is 12 feet away, the signal arrives roughly 10–11 ms later. Keep this in mind when placing mics or layering tracks—those tiny delays can affect timing and fee and can add some natural room reverb.
   

3. If the room you're recording in has a very noticeable air conditioner or central heater sound, mic everything very close or shut them down for the duration of the recording. AND... if the room is very live, meaning having too much of a natural reverberation, mics need to be moved closer to the source (voice or instrument). I you're recording in your bedroom, try opening your closet doors and the clothes will absorb some of the bounced sound.
   
   Electric Guitar Amp
   
   1. I would suggest using a dynamic like the SM57 by Shure for an amp cabinet.

   Position mic about 6 to 8 inches from the center of one of the cabinet's speakers. You can move it around a bit to either side of the speaker and see which sounds more natural.
   
   Electric Keyboards
   
   1. I would probably run the keyboards outputs directly into the mixer or audio interface. Now if you are using an acoustic piano, raise the lid and used your condenser mic toward the middle of the soundboard. If it's an upright or spinet the sound will be terrible if it's out of tune in the slightest. That's why I rely on the electrics.
   
   Drums
   
   1. Bass drum - If the front drum head has a hole in it, use the dynamic mic there. But you might want to stuff a small pillow in the bass drum to help control the ringing and make the sound more consistent. If there's no hole, just place the mic as close to the head without touching it as possible. This will more often than not be an equalization situation to get the sound correct.
   
   Snare/High Hat/Toms
   
   1. Assuming you don't have a lot of mics, place your dynamic (probably SM57) between the snare and the high-hat.
   If you have extra mics, place the dynamic mic at an angle about an inch from the head but not in the line of fire from a drumstick.
   Then use a condenser mic over the high-hat about 3 to 4 inches away.
   For the toms, you will probably need a mic situated above and between all the toms and EQ will have to handle the separation.
   
   Vocals
   
   1. Place your mic stand in front of an open closet door and sing toward the hanging clothes. That will absorb sound reflections.
   Condenser mics generally work best for vocals.
   If it's a group of background singers, position the group in a semi-circle around the business side of the mic. Still use the closet trick unless you have a padded baffle.