Don't tell your singer or rapper this, but the vocal IS the most important part of the track. I know, the truth is terrible. So, here we go on the adventure of how to record vocals. Sometimes, it will be magical. An artist will open their mouth, do the thing they do and you will be sitting there in awe. Gold. I can name three singers I recorded in my life who were like this: Amy Winehouse (dead) Nicky James (dead) and a guy called Neil Gow (not dead and should be famous but isn’t) However, more times than not...it's damn hard work and the best way to make it go well is to be prepared. Unlike everything else you record the singer IS the instrument so it's half technical, half mental.
So, what kind of mic shall we use? If you only have one decent mic - fine, then that is your vocal mic! Generally any large diaphragm condenser is a good start, but it so happens that mics often match fairly specifically to singers...for a thinner singer, a bigger sounding mic, and vice-versa. What is perfect for one person may not be for the next, so by all means try a few and don't hold any preconceptions about what you EXPECT to work best. While you can be pretty sure something high end, valve based and/or ungodly expensive WILL give you a great vocal sound, you just might find a cheap condenser or lowly dynamic is the tool for the job. I was working on a record at Rockfield, spoiled for choice having an amazing choice including TWO U67's in the mic locker and the producer I was engineering for wanted me to use an SM57! The singer was quite dirty, loud, a very rocky voice and so there we were, and that's what I used. On this topic, certain mics seem to have an internet cult following, the two biggest being the SM7B and the U87. Nothing wrong with the 87, but you know...it has a big wooly low mid bump and *always* needs EQ-ing. Same with the SM7B - great for rap, screamers and rock & roll but always needs EQ to sound special. It's the same capsule as an SM57 in a cage to keep the singer away from it as it was designed as an announcers mic. Neither of these mics are magic, and work no better or less well than others, so don't believe the hype. Your Audio Technica, or whatever you have is totally capable.
The first thing you're gonna do is check the headphones. Make sure that your singer has a nice, clear, solid mix in the headphones before they even try them on and that whatever mic you selected is coming through. Make sure you have some reverb set up on an aux ready to go - it's a very personal thing...some like to be bone dry, but often singers are actually shy creatures and like to be swimming in 'verb. Either way, it is your job to make them happy and comfortable and to be ready. Maybe they won’t even get on with headphones at all and would rather sing in the control room with the speakers on. That’s fine, face them towards the monitors, do your best to reduce bleed, build a barrier, use a little iso shield and crack on! I want to also make a quick comment about vocal booths - often they totally suck. Small spaces with a nasty resonance that you can’t get rid of, big panes of glass, all kinds of adverse things. Often it’s best to set up in the big room and use a couple of baffles, hang a blanket, do whatever.
Singers always stand too close to the mic, so as one of my less PC mentors told me (don’t shoot me, blame the 80’s) …tell them to "stand a cock's length" away from the mic which will immediately have them leaping back a foot, unless they are female in which case they will end up at about half that. Either works, we just don't want them up on the mic! You're going to want to use a pop shield unless you believe half the music videos of people recording in studios. I like to put this as far as I want to keep the singer away from the mic to reduce plosives ( the big bangs from "P" and "B" when you sing ) and depending on how much low end I need...closer to the mic, the more low end. If you don't have a pop shield, tape a pencil vertically in front of the capsule right in the middle. I know. Ancient recording voodoo from Uncle Adam. You can also swoop and move the mic up and down a little - higher for more head, lower for more chest. Use your ears. As far as processing, listen, then take action. Get your level set and leave plenty of headroom as I assure you your singer will be way louder than they are when they are singing as a test. I would almost always record a vocal with hardware EQ and compression on the way in, though conservatively - almost any vocal will need a lift in the top end, and a few db's of compression at 4:1 will make everyone's life better. Maybe even use the HPF to roll off some rumble if it's an issue or better yet - use the switch on the mic. Get ready to attenuate the gain and watch your compressor threshold as they inevitably sing louder. If a singer is sharp, turn them up, if they are flat, turn them down a little bit in the headphone mix. By all means whack another compressor on the channel in the DAW if you need to if it helps the artist hear themselves. Some love it, some hate it. Ask.
The next part really is about the performance. Honestly, it is all about the performance anyway! It takes time to warm up, but record from the beginning just in case. My advice is to make it as quick and painless as possible, and comp from several takes usually done in relatively quick succession. Then have a look back with a microscope and grab the parts needed to make a stellar performance. Just drop them in, old school. Fix, move on. Speed is good as speed means your singer is less tired. It will not always go smoothly and sometimes is the most time consuming part of the process, and here you swap hats from being a technician to being a coach. Whatever you need to do, do it to help your singer get to the finish line. Do not settle for good enough, here - quality matters. Have a warm drink ready, pay attention, make notes so you can make sensible comments about the performance. Stay off your damn phone. There is nothing worse for an artist who asks for direction to receive no useful feedback.
Even with the same setup and mic, recording on a different day can make a big difference to the sound so try to wrap up the specific part at least you are working on before you call it a day. I like to make doubles if needed as we go as the singer has the exact delivery in their head so time is of the essence. Do it quick. You can also make doubles from the alternate takes you had spare if they are good, and use something like Vocalign to tidy things up. There is nothing worse than hearing multiple lines end at different times. You want an education in stacked vocals take a listen to some late 80's/early 90's R&B - done to tape, and flawless.
You may also want to look at clearing up some of the noise, random humming, swearing, clanking mic stands, snot noises, clicks and other weird singer stuff at this point, and deal with breaths if they are an issue. Don't delete them by default, they can add character and realism, just use your judgement. Go listen to a Diana Ross track. Are your breaths that loud anymore? No. You can always turn them down in a DAW. It is however a good idea to delete the ones on BV's if in a stack and let the LV be the one that breathes. Again, this is all artistry that you need to develop to deliver killer vocals. When you're done sit with your vocalist and compile a master take of each separate part all on one track each with nice crossfades, then think about what's next. You may need to tune, or not so do that if need be, fix plosives if some made it through and render that sucker. Your mix guy will thank you!