Probably my biggest worry for when the game unlocks for me on the 20th. I am extremely picky with the characters looks, and without any way of saving sliders or especially grid coordinates I just know I will spend 10-12 hours restarting the game. Who knows, maybe I am lucky and can't play the game since my Origin has hit the very familiar bug of constantly resetting the download (took me 2 full days to successfully donwload the Sims 4 due to this) :-(
Keeping a notebook really helped me. I mean, it's more difficult with the grid system, but I'd put something like...
Eyes slider: second option, top centre of grid for size. Or hair: red, dark, 3rd option from end.
The more times you create, the more you get used to positioning and remembering.