Something that we use with some of our kiddos are first/ then cards.
They are great for students that have autism or for students that are sometimes defiant about completing tasks because they know that once they finish an activity or task they will get to do something they want to do and enjoy doing!
I like to put mine on old dvd cases so I can store the pictures inside of preferable items.
Here the child knows that once they finish their work (you may choose to use a more specific picture) then they will get to play in the sensory bin. It gives the student something to work for.