when I were a lad.... we had to use newspaper when we ran out cos we were poor.
Please do not try this at home as it BLOODY HURTS!!!
...and it didn't do avery good job either.
regarding the 'under - over' issue....it also depends on what type of hoder you have. we have one of those that i basically a steel rod that goes through the roll and the roll rests against the wall, and so you can do it one handed from 'over the top' but not from underneeth.
but if its one that has the roll away from the wall then I'd say its better form underneeth.