Blizz said they want to know what customization options we would like to see, so here is my wish list. Feel free to share yours.
Options to make males less muscular and remove hunches like orcs.
Beardless night elf with eyebrows PLEASE. lol
More earring and piercing options for both males and females. Maybe belly button rings, now that we have shirtless transmog.
Shared hairstyles across races and more colors/styles.
Human beards that don’t look like jutting pine cones.
And fair skinned Void Elves like Alleria Windrunner and those found in Telogrus Rift! xo
Also, Leper Gnome skins for Gnomes.
And seperate customization for human form for Worgen.
Color wheel eye color choices. or at the very least; a big list of pre set colors to choose from regardless of face type. 
I desperately want my female gnome to have the only neutral cute face with purple eyes please!
Yes please! Also on that matter
Just a few I could think of at this moment.
Breast Cup choices 
Elf ears that don’t stick out of helmets.
Helmets the cover the whole head of a Worgen instead of just the face.
I want a long hairstyle with curly hair and bangs for Blood Elf females.
Separate fur color and pattern options for relevant races - worgen, tauren, pandaren, vulpera. (Vulparen?)
A dye system. Come on inscription, colour my armor.
Why would a scribe be coloring armor? Scribes just write words.
They make dyes, act like I’m paper and throw it on me.
Customizable weapon scaling. It doesn’t have to be a true slider but at least the choice between Small/Medium/Large would be nice. I’m personally happy with the scaling that female BEs have now but I know a lot of people preferred it when they were smaller since they felt more realistic. If they gave all races a simple choice it’d let people that want smaller weapons have them and people that want larger ones (“stupid Anime weapons” was the phrase I saw the most) can have them instead.
Speaking of which, seperate fur color and tail for female Panderan. Right now you can’t have the long tail unless you pick the red fur color.
Fun fact: red pandas aren’t related to giant panda. They’re in a genus of their own and share a family with weasels, skunks, and raccoons.
Fair, but maybe Alchemists could? I mean either could “work” since I doubt they would make a new (but potentially cool) profession just for dyes. >.>
I feel like Tailors should dye cloth armor.
I don’t know about the rest.
I’d say either the crafting profession that makes the armor type or inscriptionists since they already turn herbs into colorful things.
Almost spit that sip of coffee all over the monitor lol!!
I wonder if the customization options need be limited to just cosmetic barber options and could also be spellcasting animations and such.
Honestly just more hair styles,colors,eye colors for all races and some options that should have been in since launch(eyebrows for beardless NE).
High Elf aesthetic (tattoos, blue eyes, pale skin, celtic hair; basically like Alleria) for Void Elves.
That’s about it.
Scribes.
Maybe we could have it like this: Scribes make the dyes, and the crafting profession that makes the armor type dyes it.
I’m going to use my made up words however I want.
That has potential. It’d be good for inscription to diversify since, to be perfectly honest, I have no idea what they do anymore other than produce the rep contracts.