Right now is a good time to go out to your lawn with a garden fork jab it in and wiggle it a bit, then a few steps later do the same.
It helps with compaction and drainage, so if we get a wet winter you wont get as many pool on the surface and there should be less moss etc.
Now is also the end of the time for getting your spring bulbs down so if you like daffs and tulips etc get the bulbs down in the next few weeks. Rule of thumb is bury them as deep as themselves.
If you have tatty looking beds and borders, cut away anything that looks brown and messy, dont worry most stuff will grow back in the spring, weed everything and mulch. Hardcore gardeners will get well rotted horse manure or garden compost for mulch, but you will still thank yourself next year for putting down some ordinary bags of compost from the garden centre now. It will keep the weeds down and enrich the soil for next year at the same time.
You should also take note of what has been doing well in your garden up to now, and make a note of wthere it's been - in the shade or on wet ground or whatever, and also what does well in your neighbours gardens. That will be very handy when its garden centre time again. Garden centre staff will understand a lot about your soil and acidity from that and they'll be able to recommend other plants that like the same conditions.
AND the best bit for this time of year. Seed catalogues are a feast for the eyes and they always say what type of soil/shadiness each plant requires. So order some, put your feet up and dream about Spring!