Wear primarily neutral or muted colors (black, white, navy, beige, grey, denim). If you'd like to incorporate bright color, it's best to stick to a single hue in small doses such as a bright blouse under a blazer or a colorful tie over a simple shirt. Any colors you do wear should compliment your eye color and skin tone

Avoid clothes featuring busy patterns, bold stripes, text, or large graphics

For family or group portraits, have everyone dress in neutrals or consider picking a theme and having everyone dress in variations of the same colors. Coordinating your family's wardrobe in a photo can serve to visually reinforce your close relationship, whereas drastically differing clothing can shift focus onto only one person and away from the rest of the group.

Jewelry should be kept simple. Transparent "float effect" necklaces and bracelets should be avoided as they look very strange under photographic lighting.

Form fitting or closely tailored garments are more flattering than baggy ones, even on heavier figures. V necks, open collars and button down shirts are also very helpful in creating a sleek silhouette that draws attention to the face.

Dark colors have a slimming effect on all body types.

In regards to hair and makeup, simplicity is key. Portraiture is all about the face and letting your own natural beauty shine through. Heavy or brightly colored makeup often looks much more unnatural on camera than it does in person. (extra tip: Lip liner is the most common culprit when it comes to unnatural looking makeup in photos. Make sure yours blends or, better yet, go without.)

If you wear glasses, decide ahead of time whether or not you want to be wearing them in your photos. (And be sure to let your photographer know your choice. I've had many a photosession where someone exclaims halfway through that they forgot they had their glasses on when they'd meant to remove them!)

Schedule any haircuts at least a few days (ideally a week or more) before having your potrait done to ensure a natural look. Hair color can also benefit from a few days to "calm down."

Make sure clothes are freshly washed and ironed. This one seems like a no-brainer, but a reminder never hurts!

Try to drink plenty of water the day of and the day before getting your portrait done to keep your skin looking healthy and fresh. This can especially help those worried about aging complexions.

Above all, relax and have fun! Genuine happiness will shine through in your photos even if you aren't giving a big "Say Cheese" grin. I find a no-fail trick is to think about a beloved pet or favorite vacation or anything else you hold dear to your heart.