I believe strongly in Non-Violent Communication as a framework for life.
One aspect of that is telling someone that their actions aren't meeting your needs in a way that is non-violent, such as "When you show up thirty minutes later than we said we'd meet, I feel frustrated because my need for respect, and safety aren't met. Can you give me your word that you'll show up on time from now on?"
The other person doesn't have to respond positively to your strategy, but if they don't, or get angry or respond in some other way that doesn't meet your need, then the onus is on you to decide what to do.
It moves control for getting your needs me from the other person back to you, and while that can be difficult at first, it's ultimately very empowering.