The biggest thing is that you want to make sure you pick outfits that you feel comfortable in. If you don't feel 100% comfortable, no matter what we do or what we try, you're going to look uncomfortable in the photos.
Think complimentary colors! Jewel + earth tones photograph the BEST! That's your burgundies, plums, olives, creams, greys & browns. Neons or super bright colors, like salmons & turquoise, are also some shades to avoid. Neons create color casts, which essentially makes your skin a different color in photographs.
Think simple, timeless clothing, and avoid big logos + branding. Lace always photographs gorgeous, and you can never go wrong with denim or a flowy dress to play with during your session!
Patterns & textures always help to add another layer to your photos! The main thing with patterns is you want to make sure whatever the pattern is, it isn't fighting with the rest of the outfits.
Plaid and polka dots are always a safe bet-- plaid flannels and flowy polka dots always photograph well and break up solids so nicely. Sweaters, jackets, cardigans-- all great as well to break up solids and to give a little bit more depth!