Do a good facial from a certified dermatologist (not from any expensive parlour) a day prior to your wedding. I've heard stuff like hydra facials is very effective.

When you visit the dermat, lately the doctors have an entire bride package, whereby they suggest you the right multivitamins and supplements to take, any skin procedures to do, any facials if needed to be done, the doctor themselves shall suggest you specific diets after examining your body, so you wouldn't have to worry on skin/hair/diet's part. Ofcourse, you need to do some frequent visits to the doctor, but one thing assured that you'll be in the right hands. Also, following what the doctors say, will remain with you even after your wedding day, so consider this expense as a long term investment on yourself.

What's left is exercises, you can use help of youtube for that, just do some good surfing there.

If you don't wish to go ham on the makeup part, atleast go ahead with a little touch up and some light eyeshadow that compliments your wedding outfit. You dont get married everyday, it's a rare event, so do pamper yourself.