The jazz group, Weather Report, recorded before a small audi ence in the studio. You'll perform better when people who appreciate you are along. A good producer will help you find your comfort zone to sing. You should trust your producer to tell you when it's good and when it still needs work. Your vocal coach can also be a positive influence in the studio.
Background vocals are another important ingredient.
Though this part will sit back in the mix, quality here will still show in the final. I think great back-up vocals is a key ingredient to successful pop and country recordings. However, getting multiple singers to sing together correctly will add to the time budget. Here are a few suggestions. Schedule a couple of rehearsals.