The Do's and Don'ts before pre-wedding photo shoot

Don’ts

• Do not scrub your face three days before the photo shoot. Your skin will be slightly red.
• Do not scratch or irritate any impurities in the days before the shoot.
• Do not try out a new hairstyle that you are unsure of before the shoot. Go safe always. You might be asked to dye your hair if you have black hair so that you can see the hair patterns in the photos. 
• Do not use hair conditioner or hair mask a week before the photo shoot to keep your hair do from falling off. Unless you opt for no hair do photo shoot.
• Don’t drink/party the night before.
• Don't skip your breakfast/lunch. If your are having an afternoon/evening session, eat a light lunch. Bring food for yourself, water (with straw for the bride) and some sweets. It takes a lot of energy to do a photo shoot and you certainly don't want to run out of steam before the session is over.
• Do not shave for a week. Leave your body hair to grow about 1cm and shave early in the morning before the photo shoot. So you will have a clean shave without black spot on the skin. (Does not work for everyone. You might want to consider waxing.)
• Do not wear black or dark color underwear. Choose white or beige color.
• Bride is advice not to wear any watch and glasses. Again, its up to personal preference.
• Do not be late to bridal studio. 

Do’s

• Follow the instructions giving by your stylist. If you have any questions about what clothes to bring, then call them. Basically, you will be asked to bring silicon bra (buy one more for backup as sweat can reduce the stickiness), slippers (if you walk a lot) and high heel (for female) - white/black leather shoes with socks, trousers/jeans with belts and long sleeves. (for male)
• Be shaved/waxed where appropriate before the photo shoot.  Girls - Legs (optional) and underarms. Male - Be shaved nicely unless you have been instructed not to. Be careful and don't hurt yourself with the blades!
• Shower and wash you hair clean before going to bridal studio.
• Have your eyebrows plucked.They won't do it for you. Well. It depends on the bridal anyway.
• Get enough sleep. It’s best to get up later then normal. Basically the shoot don’t start that early so spend your time sleeping instead of other things. Pack/Prepare your things to bring for photo shoot ahead.
• Have your nails manicured - done to be pretty and presentable. Your hands will NOT be hidden in the pictures. There'll be lots of shots which hand are on or around the face, so this is very important. Also paint your toenails.
• If your bridal studio include make-up/hair artist, go to the shoot earlier and do not wear anything like make-up, moisturizer. They will need to apply ampoules to your skin.
• Instead of a pullover, wear a button up shirt so that you won't disturb the make-up and hair when you are begin to change the session.
• Bring face towels if you think you will sweat a lot during the photo shoot.
• Bring your own accessories if you have any. Else they will use what they have in shop.
• Lastly, be prepared to smile-non stop! 

Source: http://wencykewt.blogspot.de/2011/06/pre-wedding-photo-shoot.html