How do we find a good intentional thought to replace one that isn’t serving us?

For example, “it isn’t fair” is not reality and it doesn’t serve me and keeps me feeling like a victim.
However, the following intentional thoughts don’t feel right either:
“I can accept that life isn’t fair”
“Life is just the way it is”
“I can accept that life is 50/50”

none of these thoughts seem to create strong feelings in me that could motivate helpful action.

How can I figure out better intentional thoughts? Is there a resource or list to help me brainstorm?