These Toggler hollow wall anchors are very easy to use and give good results on hollow plasterboard walls. If you need to hold a lot of weight there are better alternatives than the Toggler.
Hold the Toggler between your forefinger and thumb with one hand and push the centre of the Toggler inwards then it can be pushed through the hole easily.
Drill a hole the correct size for the Toggler and push it into the hole and ensure it is flush with the wall.