Hellobee Boards

As long as you don't need to carry a bunch of baby stuff, I just use a standard large crossbody purse for this. Tignanello make my favorite but they seem to have discontinued the ones I own (Pretty Pocket and Pretty Chic). I was able to order another Pretty Chic on Ebay for a good price a few weeks ago, though.

This is the bag (tons of pockets and fits both water & small umbrella) but I got it cheaper on Ebay:
https://www.amazon.com/Tignanello-Pretty-Protection-Saddle-A279958/dp/B01M1LDUEE

Although I carry a cross-body on a day-to-day basis, I love that backpacks have come back "in style". I find them so much easier to use while traveling. I find after a day of site seeing with a cross body makes one of my shoulders sore...especially with a water bottle.

I prefer a cross body backpack to a straight crossbody when sight seeing. I usually browse ebags and zappos for ideas.

I have the same backpack as @ShootingStar: - it's SO light and a great size and packs up super small, I just personally don't like backpacks at all so I rarely use it.

I have a plain canvas Coach cross-body that I like for traveling, because it feels safer than a backpack and the strap is wide and soft so it doesn't cut into me anywhere.

@Mamaof2: I just don't put my wallet or money in places where someone could just reach in and snag it.

Look at Kipling and Le Sport Sac!

My go-to travel bag has been a Pac Safe crossbody. It finally disintegrated after being used for ... a decade? It was big enough for a guide book, water bottle or umbrella, and other small essentials. It never felt uncomfortable on long days out seeing things. Definitely would not do a backpack!

@littlebug: Oh no!! That's a bummer. I have to watch out for that.
Oh and yes, make sure your jacket pockets have zippers if you go that route. Also inside pocket or shoulder pockets are helpful!

My favorite is a generously sized leather Furla crossbody bag. It's big enough to hold everything, and the leather of the bag and strap are thick enough that they can't be easily cut through. I just switch shoulders so that they don't get tired. I have something similar from the Coach outlet store (less than $100 with coupon) that is a little smaller with a narrower strap that is my second choice bag.

ETA I recently got DH a buffalo leather bag inexpensively ($60) from Amazon that is great and they had several crossbody options with wide straps. The leather smelled odd and took a few days to defunk before DH started using it, so that could be an option too!

For serious travel I typically take two bags. I have a bagalini crossbody and also a longchamp tote. The longchamp can be fully folded and takes up zero space by also looks decent enough to go to dinner with and carry essentials and a light sweater. I've even carried my heavy dslr in it in a pinch. It's not great for all-day hauling but it's really versatile.
If it's a high-crime or touristy area I use a mini carabiner to clip the two zippers together and flip the bag so any exterior pockets face me.