Tree leaves have been slow to fall, so maybe use the mower and bagger attachment to go over the lawn one more time to clean up the last of the leaves. Ground up leaves can be used to cover the vegetable garden soil for the winter, or be added to the compost pile or bin as part of the "browns" to go with the "greens" already there.
Once you are finally done with the mower, time to put it to bed for the winter by adding fuel stabilizer to the gas tank and running the motor to get treated gas into the carburetor. While the engine is still warm, drain and refill the crankcase with fresh oil. Clean the underside and outside of the mower, change or clean the air filter and even sharpen the blade. Since you are likely going to use the gas in the can to fuel the snow blower, add some fuel stabilizer to the can as well. Two cycle blowers have the oil and gas mixed and could benefit from the stabilizer too. Either add fuel stabilizer to the blower or from the treated can and go ahead run the blower. If your garden shed is like many others, go ahead and swap out the blower for the mower so it is easy to get to the first time you need it.
Some projects potentially left undone or unfinished could involve protection newer plants from the winter winds and sun, especially if they are needle or broadleaved evergreens. Temporary screening or using an anti-desiccant will work. Small plants can be protected by covering with evergreen boughs or even branches that will catch leaves. This has the added benefit of being disguised and hidden from rabbits. Any rabbit fencing put up should be pressed into the ground to be frozen in later to prevent rabbits from burrowing or pushing the fence out of the way. Rabbits will stand on their hind legs or climb up the snowdrift so be sure the fencing is high enough to be effective.
The last couple of things to do at the very end of the season are to clean up those gardening tools for the final time and to remove the hose from the house, drain and put away for the winter. If you leave the hose with water in it, freezing and thawing will break down the hose components and it will not last. Perhaps even a bigger deal is that while homes come with a frost-free spigot now, leaving the hose on can mean there is water left in the spigot that can freeze. These are the last two since watering late into the season is critical to all our plants, young, old, recently planted. Even if you had already cleaned the garden tools, you have likely used at least some of them again, since that is our nature as a gardener. See, you did work some of that turkey off.