The short answer to this would be to wear what makes you feel comfortable. If you're here you are most likely looking for a more detailed explanation though. However, being comfortable should always be where to begin first when planning what to wear. A quick Google search will give you lots of ideas but it can also be overwhelming. That is why we have to start small. If children will be a part of your photo session, I would start by building excitement with them. Why not ask them what they might like to wear and what are their favourite outfits (don't forget the spares too!). Then, you and your partner can work in coordinating with them. The most important rule is to not wear anything that doesn't match your style. Don't overdress if formal clothes aren't usually your thing and don't underdress so that you feel uncomfortable. Simply, dress for the occasion. Your gorgeous high heels just won't cut it if you plan a hiking trail for your photoshoot location. Avoiding patterns and choosing solid colours instead helps to emphasize your face and expressions. It's also a good idea to avoid brand names or logos written on your shirts, etc. as this can be distracting to the final image. In the past, it was trendy to all wear one colour or the same kind of outfit. The downfall to this is that everyone might not want to wear what is agreed upon. Then, the result is uncomfortable people trying to make an effort to smile and feel confident. Grumpy faces certainly do not complement your photos! A compromise to this trend however is to choose a colour scheme so that you are all dressed in complementary colours that look great on you all and work well with the season and location you chose. Check here for a blog post that explains in more detail about dressing for a summer photoshoot.