Callistemon21
I've found going on to your hands and knees, then going into a semi downward dog (yoga) then walking your hands back makes getting up easier.
I think, as Calli suggests, practise and get inventive according to your own ability. Obviously a mobile 'phone is a wonderful comfort, especially if out walking. Indoors, some of the suggestions from this Occupational Therapist's video with regard to being creative sound promising.
I don't have any stairs but they can be really useful after falling indoors, especially for those who really can't use their knees.
If you fall and are struggling to get up off the floor, a bottom shuffle to the bottom of the stairs, turning around and then using the stairs to sit upon to whatever height, whilst firmly holding the spindle, should get you to your feet. An upstairs fall? Another bottom shuffle or similar to the top of the stairs, gradually sticking your legs over the edge and choosing a tread whilst holding tight to the spindle should ultimately put you in a good position to sit up with feet braced (maybe one, below the other) and the 'oomph' needed to stand up again when you're ready.
www.youtube.com/watch?v=4ETgQD8QhZs