This is so quick and basic to make:
Print and cut out one of the many free colouring pictures of Jesus ascending to heaven. (I reduced the size of mine to fit the opening of the paper cup, and glued it onto a piece of card to make it a little sturdier)
Glue some cotton wool to a blue paper cup (you can also cut out white clouds from craft foam).
Make a little hole just above Jesus' head and thread a piece of embroidery floss through it, then through a small slit in the bottom of the paper cup, and sandwich it between two white cardboard clouds.
Write an appropriate Scripture on the cloud - I used Matthew 28:20:
I will set this up as follows: Make a 'mountain' by turning a mixing bowl / shoe box / laundry basket upside down and covering it with a green cloth / sheet /towel. Place peg doll disciples in a semi-circle on the mountain. Position Jesus among them and as you tell the story of how Jesus was taken up in the cloud, pull the cloud so Jesus disappears into the paper cup 'sky'.
(This is not a great photo, but it was a little tricky holding onto the cup and trying to take a photo!!)
We will end this with singing two songs my children know about Jesus returning for us one day (For my local readers: Hy kom weer op die wolke - Oom Karolus en Lente; As Jesus kom op die wolke - Jan de Wet en die Loflaaities.) I also have the full-size colouring page ready which I used for our Jesus figure. You can get it here.