One thing that I used to do and need to get back to is menu planning. If I plan my menus ahead of time, and shop according to my menu plan, then I should be able to shop ahead for what I need.
One other thing I already do, and probably need to expand a bit, is I have a few different quick meals or desserts that I always keep ingredients for so that if I need a last minute snack or meal to take somewhere, then I'm prepared.
So, here's to changing my habits one at a time to help me achieve my goal of a simpler and less stressful life.