Tip 1: Think Coordinating colors, not necessarily matching colors.
Tip 2: Keep it Simple. Avoid logos and graphics for portrait sessions. Busy patterns are not a good choice especially if they clash with other patterns in the shoot.
Tip 3: Don't wear too many bulky clothes or clothes that are overly large in size. The bulk will make you look less person-like.
Tip 4: Accessories! Don't be afraid to use some accessories in the shoot. This could be hats, scarves, sunglasses or jewelry. Even for Children! Just don't overdo it.
Tip 5: Natural hair and makeup for women looks best. Try not to overdo it with updo hair styles. Don't use too much makeup with colors and such that you would not normally wear. Natural looks great. You may want to powder before the shoot to minimize shine and reflection.