I use two different skins but I swear by Llumisims Freesia skin. Both of the skins I use are head to toe skins. Here's an example of both the male and female versions of the Freesia skin...
https://i.imgur.com/wzoU7N7.png
A tighter closeup of two sims using that same skin
https://i.imgur.com/g5c9274.png
It doesn't alter their features like a lot of stronger alpha skins do. It smooths out their features and freshens up their looks. I only have one sim that uses an alpha skin. This one is S-Club's Bassis 6.0...
https://i.imgur.com/TsDvWwU.png
One last picture to highlight the difference, Freesia on the left, Bassis on the right
https://i.imgur.com/zaoCXhu.png