I didn't want to make the title 'What's the one thing you need to do... ' etc because obviously no-one should feel pressured to do anything!
I guess I mean what's the one (or perhaps two) things you wish to pay more attention to?
Last year I decided to be quite religious about applying sunscreen to my face daily. It has made a big difference to my skin, I can see it.
Now the one change is to cut out alcohol and really hydrate properly.
(And as a second, I need to pay more attention to my hair... styling it I think).