I used to tie leaves and stem in a sort of knot above the bulb and when they died they were easy to collect up and were not flopping all over the ground. However I realise this might be a bit over obsessive! It worked for me though and kept the garden tidy.
I also used to do this many years ago, but tieing knots into the leaves apparently prevent the leaves feeding the bulb (which is the whole point of leaving the leaves on in the first place).
I got round the problem of floppy daffs by planting Tete a Tete which are very long lasting, and have leaves which don't look too untidy, as they are only about 9" tall.
So now I just dead head them, leave the leaves for 8 weeks or so and feed them.