honestly i really like playing with vertical sync on. People say it induces input lag, but most video cards come with an option to sync up with your monitors refresh rate, and that seems to work the smoothest for me, no screen tearing, and no input lag. If you dont get frame drops, i think this is the way to go but im probably dumb.
If it helps at all, back when i had a pc that didnt have that setting i would just set the cap at refresh rate x2 +1 because thats what would look the smoothest to me, although honestly i thing not having a cap is fine but people think it puts unnecessary wear and tear on your pc.