For UK snuffers, a 20 pence piece does the job. I’ve used knifes and screwdrivers, both not as effective as the aforementioned coin.
I’ve found the nail technique works particularly well: Start somewhere on the edge and lift with a fingernail or two, then move about an inch and do it again. By the fourth movement, the tin opens. I didn’t believe it when I saw the Six Photo gent do it, but it really works… The important thing is to only move about an inch to an inch and a half. That seems to do it.
I’ve used my can opener in a way that doesn’t break open a can but, rather gives me leverage. I use the pointy side but, the way it is shaped the pointy side doesn’t even dent the can.
I favour the 50p piece. It’s not as difficult as some people make it seem.
I agree with @peppernut1 - people make a right song and dance about it. Quick twist with a 20p or 50p and you’re sorted. It’s the same with Viking tins.