My clients often ask what they should bring to a session or what they should wear - so here are a few general suggestions!
What to wear - Wear something that will pop with your background but that still look like you, something that you are comfortable in. Usually, I suggest light, neutrals colors (white, tan, light soft pink or mauve, or gray) with maybe some pops of color like navy blue, gold, army green, or burgundy.
I definitely discourage brighter colors such as yellow, red, orange, lime green, or pink as these don't photograph very well. Why? Bright colors can create a bad color cast on faces and really look strange in a photo. They also tend to really not photograph well - the color will look brighter than you would think and might even hurt to look at just a little bit.
I also suggest that everyone not have exact matching outfits but instead simply look nice together. Coordinate rather than be matchy. Blacks and darker colors are fine, BUT they tend to blend in with the background a bit if we are shooting outdoors in nature (in the trees or where there might be some shade). So keep location in mind. Long flowy dresses that are light and can move in the wind photograph well and add drama and motion to a photo. (Try looking online at Forever 21, Free People, Lulus, and Asos).
What to bring - Bring things that are personal to you - maybe kids' favorite toys to help them feel comfortable. Bring things that will add to the shoot - like a blanket to sit on, for example. Or if you are planning a themed shoot, bring something applicable - maybe a picnic set up and balloons or a cute bicycle. Don't bring so many things that you are carrying armfuls between locations - the in between moments are important and often make some of the best photos but not if your arms are full of props.