When sampling off a record...

When sampling off a record...how do you sample just one instrument? or, are you supposed to sample a short loop? What do you do?

You're not supposed to do anything. Do whatever the **** you want.

You sample what you 'hear' on the record. There is no way you can for example only sample the drums out of a record when you hear drums and bass and guitar at the same time. You could try to filter out certain sounds in the sample but that will result in an overall quality loss of your sample