I like to use a crossbody bag that I can slide behind my back and pull forward for easy access or extra security. I had an old model from Baggalini, but it got worn out and it's no longer available. Their current models are more purse-like, not really suitable for a man.
I don't like using a backpack or bag that goes over one shoulder like the Veloce Shoulder Bag or Civita Day Pack. I've struggled to find a bag that is well-constructed and well-designed, but I recently discovered the Vanlison large shoulder bag. It's the perfect size to carry a small laptop and all the accessories I might want while walking around town. I haven't taken it on an overseas trip yet, but I've used it around town and on a recent road trip, and I'm very pleased with it.
It's available on Amazon. There are a lot of other models from Vanlison. They are well-priced, especially considering the quality. Worth considering if you like this type of bag.