Here are a few tips for when you're planning out your outfits...
Coordinate but don't match
Pick out a few color choices and go off of that. Usually have one person that stands out with a pattern and take colors from that for everyone else's outfits, keeping them more simple.
Add layers and texture
Adding layers and texture to your outfits helps to add interest in your photos. For layers just adding a simple scarf or jacket will give that little pop needed. Texture can be anything from lace, ruffles and crochet. Do what fits your style best!
Go for comfort
When it comes to dressing children for a session you want to make sure they are comfortable and can move around. Having an outfit that isn't comfortable for the child can make them grumpy for the shoot. Also I suggest if you're going to do an outfit change on a child only do one change. If you want to have a variety in the outfits just add a jacket! Adults need to also make sure they pick out an outfit they feel comfortable in because it will show in your photos if you weren't feeling comfortable.
Accessorize to add a pop
Accessorize your outfit with scarfs, jewelry and hats. Just don't let the accessory take over the photo, you are the one that's supposed to stand out!
Shoes do matter
Your choice of shoes can help an outfit or hurt it. Wearing cowgirl boots when your shoot is going to be taken in a field works perfectly! Adding ballet flats to your dance theme shoot is helping to complete your outfit. Sometimes no shoes is best. Please just don't wear your old gym shoes to a family shoot, etc. Only time gym sneakers really work is if it's a senior session that is sports themed.
Patterns are fine
Don't be scared to have patterns in your outfit choices, patterns work well in moderation. Usually only have one person in a pattern and the rest in simple more solid pieces or make sure any other patterns are subtle and complement each other.
If you need more help with outfit ideas you can head over to my Pinterest page that has different outfit examples!