In uk.d-i-y, Pablo wrote:
I've got myself some Heavy Duty RediDrivas from screwfix. How do I use them?
Do I drill a hole first then screw in the base then the screw?

You don't have to - the pointed bit on the end will cut its own hole.
But I find it handy to drill a pilot hole with a small (5mm say) masonry
bit. Firstly, I find a masonry bit more controllable (no hammer action
for plasterboard, of course!) than the RediDriva; secondly it lets me
be sure what's behind the plasterboard - empty space, in which case the
RediDriva is the fixing I want, or a stud, in which case a longish
woodscrew straight into the wood is more appropriate. (You can feel the
difference right away between the masonry bit going through the plasterboard
and coming into free space, versus hitting wood behind - since masonry
bits aren't sharp enough to go through wood easily). Don't push hard on
your drill if you do this - you don't want to tear big pieces of plaster
away from the back of the plasterboard as the drill comes through, since
you want the plasterboard as intact as possible to hold the RediDriva.

HTH, Stefek