Firstly, what exactly is a small win? This is an activity which you do successfully but weren’t sure you could actually pull off. Like cleaning a small pile or closet. Like getting rid of old stuff.
A bunch of small wins equals significant change. Step by step.
Notice it and get excited. Think back to how it was and how it is better now. Bask in the victory of having achieved it and it will give you encouragement to continue.
Reward yourself. Of course, the cleaner house is reward in itself. But you can also acknowledge and reward yourself for the hard work you put into making it better. But don’t slack off now; don’t rest on your laurels. Keep moving forward.
As applicable, communicate it. Share with others. Talking about it makes it more celebratory. It may even encourage to tackle their own messes.