Avoiding resentments, for me, starts with acceptance; acceptance without judgement.
When someone does something that might upset me, my first thought tends to be that they are WRONG!
When I can short circuit that anger and judgement I can usually accept people for who they are.
Then I can see that usually their actions are not directed at me, personally.
Then I can do what WMJ1012 suggests and not take it personally.
I cannot do this every time, but I pray for this ability -- to see with acceptance -- daily.
Things are improving for me and for those around me.
I also have to accept that I am a slow learner when it comes to interpersonal interactions.
When I sit in judgement of another's actions, am I not playing God?
Consequently, I have lost the humility that I need to accept my Higher Power . . .
The humility to be able to recover from alcoholism.