When there have large holes to fill in walls or ceilings you have to create a base for the filler to sit on or fill the hole gradually over a number of days.

The fastest method I’ve found is to fill the gap with strips of bubble wrap & then a layer of damp tissue – this fills the big gaps leaving a good surface for the filler to adhere to

It is still a good idea to work from the edge of a large hole inwards with filler & leave it for a day before adding the next layer.

Have you tried it? What do you find works best for you?