These posters will catch everyone's attention including your students as the build a growth mindset.
Instilling a growth mindset takes time
Have a growth mindset about instilling a growth mindset!
It can be challenging to help students develop a growth mindset. Students will not adopt a growth mindset right away; it is a process. Try guiding students towards it little by little. For example, if a student perceives just one hard problem as an opportunity to grow, that's a good start.
Put another way, have a growth mindset about instilling a growth mindset! It will surely take time and effort, but it gets easier, and it pays off with more motivated and more interested students.
Think of a student who had difficulty acquiring a certain skill. If you could revisit that situation, how would you approach that student to encourage a growth mindset?