This is known as the safe way how to carry your things with you while cycling from A to B. The Safe Way - if your bike is without any kind of rack.
Then, of course, you can step up your game by putting your bag on bicycle handlebar. It is known that this may affect your ability to maneuver ... still it is a way how to get your things from A to B when cycling.
Or just carry your bag in one hand while the other one is on the handlebar... This might be even sketchier, but still, a way how to get from A to B.
If it gets really hard to cycle with your bag... you can always hop off the bike.
Although, we believe that you should just upgrade your bike with some front rack. It does not have to be a basket (leave it for the woman). As you can see it is chic, easy and lets face it - you can carry a lot more if you have to.
Spoke too soon about baskets and leaving them to women... This one suits the handsome gentleman really good.
Happy cycling!