Right-handed people tend to put their left hand in front when preparing for a fist-fight because it’s their strongest punching hand for the first hit. In this pic, Ezra’s right hand is in front, so I thought he was left-handed.
But here we see Ezra doing a lot of right-handed-people movements while handling both his lightsaber and shooting with it’s blaster.
Here though, we see Ezra putting his left had over his right hand. Usually, the hand with the stronger grip (and therefore your lead hand) is placed on top. So if Ezra was right-handed, his right hand would be on top and not his left like he’s holding it here.
Here’s Ezra getting Kanan’s lightsaber taken from his right hand though.
And yet here, he uses his left-hand to tell the fyrnock to attack the Inquisitor. right-handed people have a habit to instinctively use their right hand first to execute an emotional action. And yet here, his left is leading.
And again here in promotional art, Ezra’s left hand is the one holding the lightsaber.