Someone asked this question recently and while I couldn't immediately think of anything I have changed that would qualify, I wanted to hear what you all might come up with. Little changes can make a big difference!
What a great question.
Little boundaries can bring great returns.
I like my natural greying hair. I should never have colored it in the first place.
Learning about astrology did! ? Seriously, coming from a dysfunctional family with enmeshment issues, what may seem obvious to some needs to be explained to others, and learning to understand energies helped me view things for myself in a totally different light.
I thought of a big one: separate bedrooms!!! What a relief to be able to sleep with all the blankets on and without the snoring! Totally saved our marriage. And two beds are better than one - much more fun! 
Our 4th dog has also brought us a lot of joy. He sort of reset the situation here and we all needed it!
When I dropped the end of the tug of war rope with my husband things improved exponentionally 
@jana I love that imagery. Not a new one, but such a perfect one to slip into my net of give-and-go with the flowness. That rope can so easily become a noose:/