hau Dan, first I have a few questions, then I will go ahead and give you a short version of ideas to help the lawn along over the winter and some spring things to consider at that time.
I am assuming you live in an area that restricts what you can do yard wise, since you aren't asking about what veggies or
trees to plant.
Now the questions: 1.) Sun light, is this north facing property or south facing property or a combination? you need to know what varieties of grass will thrive in your space.
2.) Have you tried poking a stick down into the soil to see how compacted it is now? compaction will tend to be hard to push a stick into or it will break the stick. This will tell you how much aeration you will need to do.
3.) Are you concerned with having a nice green space through the winter? If you are in one of those areas with lawn regulations. Nothing beats having the greenest lawn on the block, it will drive your neighbors crazy or impress the hell out of the lawn snobs.
Now for some ideas and suggestions for lawn care.
1.) You will want a soil test, this will tell you the health of the soil acid/ base wise and give you a current mineral profile. You need to know what you have before you start amending.
2.) You can get air into the soil and also de-compact it with a broad fork, go lightly here before winter. In the spring you can get more heavy footed with the broad fork. An English garden fork will work almost as well.
3.) Find some good quality, known to be poison free,
compost and spread a light layer of this over your just aerated lawn and water it in.
4.) I liked to over seed for winters with rye grass, it gives you a nice looking green space all winter and when you cut the lawn in the spring the rye grass will help with new seeding sprouting.
5.) Get a spreader, it really helps get seeds and green sand where you want it. Green sand is a very nice amendment for most lawns and gardens.
Now on the chance that you can and want to create a wonderland of food growing plants, a good drawing of what you have currently is a great way to be able to plan garden areas blended with lush paths. Over lapping gardens, layered low plants to tall plants can give depth and add drama.
Feel free to Moosage me.