I just unroll them. the fewer times you move them the better.
Everytime you bend copper, it gets stiffer.
I use big motions, to get large sweeps.
That would be holding them near the ends.
I have purchased a new Moen kitchen faucet and the copper pipes at the bottom of the faucet are at a 90 degree angle. Moen said to carefully unroll the pipes. What method is recommended so as not to damage the copper pipes?