piece of paper, pen and just write the alphabet, draw a sun and a moon, hello, goodbye, and the numbers 1,2,3,4,5,6,7,8,9, and 0 then yes and no or do it on cardboard. i use paper.
before you use it be sure that you know how dangerous it is. a lot of spirits disguise themselves so be really sure before you invite them in your personal space because you never know what comes next