I attended a workshop many, many years ago and they used photos to spark discussion at each group of teachers. It was fun and easy to open up.
Have you ever seen the Blue Day Book by Bradley Trevor Greive? I can't help but love the photographs. I picked up a few of his other books and began cutting the pages apart.
This is what I ended up with
I will ask students to choose the photo that best represents how they feel about ___________ (test, math, next year, etc.). Sometimes they will share out with the group or I will have them write about it. This has worked well with groups who have been more hesitant to share or open up.