As someone who's babysat since she was twelve years old, nannied for a total of about three years, and is constantly spending time with my little niece and nephew, I've learned quite a few things about what should and shouldn't be worn when around kids (sometimes the hard way!). After all this time I think I've come up with a pretty good system on how to properly dress when nannying or babysitting. Here is my advice if you have a nanny or babysitting gig coming up and aren't sure what to wear:
Wear comfortable shoes. Little kids are full of energy and expect you to be able to keep up. This is so much easier to do when wearing comfy shoes. You'll be running around, dancing, and giving piggy-back-rides, so your feet will need all the support they can get. Converse, TOMS, sandals, and comfy flats are all good options that can also look really cute.
Dress for the weather outside. Kids love playing outside and going on walks, and it's a great way to get some of their energy out. So make sure you're dressed appropriately for the weather. If it's cold out bring a jacket, if it's hot and sunny out put on sunscreen or wear a hat. When you're comfortable you'll have more patience and more fun, which means the kids will be happier.
Wear fun, kid-friendly shirts. Not completely necessary, but I think a good idea. If you wear a shirt with Disney characters on it, the kids will relate to you more and even feel more comfortable around you. Plus it's a good ice breaker if it's your first time meeting new kids. If kiddie shirts aren't really your thing, you totally don't have to wear one, but bright colors and fun patterns are a good option too. Just anything kid-friendly, save your "Legalize Marijuana" shirt for the weekend!
Don't wear anything that you'll be devastated about if it gets ruined. Babysitting is not the time to wear new, expensive clothing. You'll probably get pretty messy, and depending on the kid's age, you'll have a variety of yucky stuff on you at least a few times. Dirt, spit up, food, paint, boogers, throw up, pee; all things I have had on my clothes, and some of those stains aren't easy to remove. It's even a good idea to have a change of clothing in your car for back up. Lucky for me I was at my sister's house when I got peed on, so I just borrowed her clothes. But if it was at someone else's house I'd be stuck.
Keep hair ties in close reach. I usually always have one around my wrist just in case. On most days I put in the effort of doing my hair, but sometimes it's just easier to have it pulled back. It can get dirty and just be in the way. So if you pull it back it's one less thing to worry about.
Don't wear really short dresses or skirts. And if you do wear a shorter dress or skirt, wear dark tights with it. You're going to be on the ground playing a lot and it will get really annoying having to pull your skirt down and adjust so the kids don't see too much! Plus it looks unprofessional to parents.
So for me, comfort is really important. All these are my own personal opinions and what has worked for me. Other people might prefer a pencil skirt and heels to nanny, but this is just what I have found works best. Hope it helps if you are going to babysit or nanny soon!
Did I miss anything? If you are a nanny or a babysitter and have any more advice to add, please share in the comments!