I encourage you to take a little time and think this one through beforehand. The outfit(s) you wear can easily enhance or take away from the overall look of your photos. Personally, I feel solid colors and subtle patterns really add a lot to a great photo, as well as layering. Loud patterns are good, but definitely when kept in moderation. Having multiple patterns can add texture, and when done correctly, will look fun & fabulous; but this tends to be tricky to pull-off, so consider getting a second opinion if you're unsure. I try to steer people away from wearing something with a large logo or easy-to-read words, because that will be the first thing someone's eyes are drawn to when looking at your portrait. Also, avoid neon or "hot" colors. They can create color casts on your skin which are tricky to remove in post-processing. For family shoots I recommend not getting all "matchy-matchy" by dressing everyone completely alike. That style has come and gone. Pick a few complimentary colors and stick with those. Hats (not so much ball caps), scarves, headbands, chunky bracelets, and other accessories can really add a unique and fun look, so feel free to bring some along to try.
For maternity sessions, I recommend avoiding horizontal stripes or clothing that doesn't accentuate your adorable belly. Ladies--especially senior girls, be sure to wear a little extra eye makeup than you typically do. It's amazing how much better it can make your photos stand out. If you are concerned about modesty when it comes to wardrobe changes on location, not to worry! I have a free-standing pop-up changing room to provide that extra bit of privacy and comfort. If you have any additional questions, don't hesitate to ask. I'm willing to go through your closets with you or even on a fun shopping spree to help however I can!