I got a bit tired of seeing the same faces at every settlement I had, and that's where ArchGaden's Spawnable Unique Settlers came to the rescue.

These are around 100 (134 at last count) Looks Menu presets that I ended up making to fill the ranks of my settlers. They're grouped together largely by hair colour or race and have tried to make a diverse group. You could of course use them for your main character but there are plenty of mods that have focussed on perfecting a single character, this is more about quantity if like me you're trying to make you're settlers as unique as your settlements.

Also I know it's a pain having to download a ton of mods before you can run a preset file so I'll not include any of them as mandatory (other than looks menu obviously), in case you just want to use the base facial structures without hair or makeup and such and decorate them yourselves. However if you want the presets to appear as they do in my game you'll require the following mods:

Commonwealth Cuts by imAarwyn (probably for most hair styles)
Looks Menu by expired6978
Looks Menu Customisation Compendium by AGodComplexPikachu (would recommend you do use this)
Lots More Female Hairstyles by rbddc12 (although mostly I used commonwealth cuts/azar ponytails/KS hairdos)
Ponytail Hairstyles by Azar azarkiowa (for quite a few hair styles)
Soul Survivor Reloaded - Immersive Afro Hair Redux by Jinxxed0 (cos seriously, all those hair mods and not a single afro?! Still, only used on 1 preset)
The Eyes Of Beauty Fallout Edition by LogRaam 
Vivid Hair Color Extended by GothikaGeist (I used the less saturated version - tbh you can live without this one)
Synth tattoo (looksmenu Overlay) by GrimSovereign (there's I think only three synth presets, so if that's not your bag don't bother)
KS Hairdos - Addon(s) with Physics by oeliza (Hairstyle maketh the face... hence four hair mods used)