This is such a simple idea, requiring virtually no equipment, and which will engage your toddlers for at least half an hour.
Depending on your toddler, you can adapt it to focus on cutting and sticking different shapes (triangles, circles, squares etc), different colours, faces and facial features, people, animals, furniture, transport, letters and numbers - whatever you like!
Equipment - PVA glue and brushes (pritt stick type glue sticks also work fine), scissors (optional), paper/card from your recycle box (to stick the pictures to) and magazines (again from your recycle box).
I grabbed a couple of magazines from the top of the recycle box, and also some pizza boxes.
I cut the pizza boxes to create good firm cardboard squares for sticking.
I started off by tearing up some of the paper from the magazines to give them something to get started with, and to show that it was ok to tear rather than cut.
C. spotted his scissors (left handed) and spent most of the next half hour practising his cutting - he still finds it really tricky to get his fingers in the right place in the scissors and perfect the opening and closing. He didn't stick much on his piece of card, but he was a lot more confident with his cutting at the end.
Bug spotted the brushes and glue. She didn't stick much to her piece of card either, but in her case it was just because she wanted to brush the glue on to the cardboard (she kept asking for more) and wasn't interested in the paper at all.
I let them get on with it, occasionally lending a hand with C's scissor grip or retrieving a brush or bowl of glue for Bug, while modelling one way of sticking a collage. I made a collage of a fish tank!