Rough guide to mix vocals decently if they are recorded well (rough and in general, so don't take this super literal, this is just a good starting point):
1.Make sure it sounds allright, no ploofy bass (no frequency content around 20hz that booms up), no pop, poofs or any other air noises like harsh 'S' sounds ect ect.
If this does happen, use EQ automation/multiband compression or just straight up re-record to remove these mistakes.
Be sure to do this in a seperate project since reduced latency in the project will help you accurately pinpoint where in the timeline there are tiny areas that you need to automate to tackle these issues.
2. highpass the vocal in the 100hz-500hz area, move it from 20 hz up untill you start hearing your vocal losing bass, then move it back up a bit.
3. High shelf your vocal slightly around 3k-15k (2Db-8Db boost)
- This step is to compensate a inherent quality of all mics, make sure you dont boost S sounds and P sounds in a way that makes it very harsh.
--if it does get harsh: back the shelf down a bit or use multiband compression to keep your high frequencies but to press it down whenever it gets to being harsh and unbearable to listen to.
3.5. grab a 4-6Db boost and sweep it through the vocal untill you hear something 'blegh' usually around 300hz-450hz it can sound awfully like it's in a cardboard box, around 800 it can get a bit... like the person is talking like squidward. around 4khz-7.5khz there can be some breathing into the microphone like F and P sounds (wich can usually be helped with multiband compression/de-essing, wich is the same thing)
Then when you find these 'blegh' spots, wiggle it around to find the exact center of the problem frequency, meaby play with the Q of the band you're sweeping with to see if it's a broad area that sounds 'blegh' or a smaller area.
Then proceed to drag it down untill you 'tuck it in' to a point where it's not a problem.
BIG EXTREME WARNING OF DANGER AND STUFF:
DO NOT, I repeat, DO NOT!!!! just drag the band down to eliminate that frequency as it will leave your vocal sounding thin and/or wierd in a way that's not good, usually 2-4Db reductions will be enough to tuck something in if it's slightly 'blegh'.
There are some cases when you have a huge ringing, it's the same thing, but try to not take too much out as you're going for tucking things in, not deleting it from existance.
4. Compress the vocal in general:
Why? You want your volume to stay over your instrumental so you can hear it.
Start out with a 1:3/4 compression with generic attack and release settings (they are used to make your first words in centences or first words in general have a bit more vollume at the start, but if you keep the attack under 5 ms and the release around 100 ms you should be fine and not have to think about it untill you are ready to look into how compressors work)
then just pull it down untill you get a 6Db-8Db reduction. and then pull up the compensative gain up with roughly the same amount, meaby a tiny bit less.
5. apply reverb/delay.
Most of the time you dont want to add too much, meaby a small room reverb with 10sh% mix just so it has a subtle room thing going for it wich will help it sound ... not shit.
Things you might want to consider based on context:
Slapback delay, a delay set to roughly 70 ms wich will not be in time, it's been made popular by using tape copying wich has a ~70 ms write speed wich caused delays wich got overused for a good couple of years and it's sticking in people's liking.
Quarter note/8th note/16th note delay:
having a diffrent interval left and right:
My favorites: 1/16 and 3/16 (instant nonstalgia on everything you do this on), 3/16 and 5/16, 3/8 and 5/8. These last 2 just groove like a mothertrucker.
Advanced trick any producer might want to get into since it's commonly used by grammy winning engineers like Dave Pensado (Beyonce and a buttload of other stuff on his name):
Have your vocal send out to 5/7/9 tracks wich all have the same reverb/delays/effects ect ect.
then proceed to pan these tracks equally out with 1 track in center and then have the tracks go out further to the right and left, this does not have to be symetrically as long as they all are roughly the same (L 90 - R100is okay, L90 - R55 is not)
Then proceed to add a standart delay plugin to all the tracks except for the center one and make it so that the furhter away from center the track is the higher the delay is, these delays do not need to be super symmetrical either, but it's best to make sure they are reaaaaaaaaaalllyy close. And we're speaking about 0.5 to 1.5 ms here.
Make sure that the entire 'spread' sound you're doing here is roughly 5ms-20ms on the most far out track so it becomes a subtle spreading effect wich gives a vocal a bit of a 'wave' sound wich can make certain types of vocals really dramatic without actually making any real big diffrence in how it sounds, but a huge deal in how it feels.
Super duper bonus: Microtune the vocals spreading out a tiny bit off (2 cent max on the most spread out one, and 2 cent is drastic here. usually 0.8 cent is more then enough.)