Anyone who has recorded vocals to tape knows there is a difference between a heart-felt performance, and something that does not quite cut it! There are certain steps that I take to ensure that my own performances are the best I can muster.
First and foremost is get enough rest the night before. This is a given. Your body is your instrument and it has to be in tune. Sleep is by far the most important aspect.
Water is the next most important. Not only during the performance, but the day before is essential. Get hydrated. Your chords will need to stretch, and the easier it is for them, the better control you will have.
Something that many performers overlook when setting up to do a recording session is the psycological aspect of it all. This is something that every performer knows and feels, yet it is unspoken in all the advice I have ever found. I particularly like the microphone pointing down at an angle to me, and I find that I can get more 'feel' if I am singing at an upword angle. Try taking a look at how you stand, where you are facing, who is in the control room … lighting, incense, and overall mood. You may find that something completely psycological may improve your perfomance 100%. Everyone has their 'thing'.
A good performance comes not just out of the time performing to the mic, but the preparation, setup and mood of the whole session. Keep these notes in mind next time you go to lay some vocals, and you will get the best performance possible.