E.S.
I have a three year old and have been doing crafts with him for a while. His favorite is using the shape punches
(we bought a circle, snowflake, Christmas tree,triangle, and square. Occasionally we use glue sticks and glue the cutouts onto construction paper, but for the most part he is happy just punching out the shapes and playing with them. Some of the punches do not collect the punched out shapes, and other do. We use them to make bookmarks and things like that!
Another project my son loves is making masks. We use construction paper and just cut eyes out and glue on feathers and things like that.
We made ghosts for Halloween that we then hung from the tree out front. He LOVED that. We took cheap white fabric, covered a foil ball, and wrapped a pipe cleaner around the neck. Super easy and no mess!
We have also made Christmas ornaments. We did a few out of construction paper and then others where we bought a wooden frame and he colored the outside.
I hope these ideas help. Bed rest is not any fun. I am 36 weeks and have been having to take it easy for the last 4 weeks. I am not on bed rest, but still trying to come up with fun things we can do while still not over doing it. Best of luck!