Remove debris (leaves, branches, litter) from the beds, lawns, decks, patios, cellar stairs, driveway, street next to the curb.
Some people want it done weekly from about the last week October. Ending in the first week of December. I try to do 3 visits before Thanksgiving and 1 visit after. I use Thanksgiving week as an off week if I am caught up.
Then there are people that want to wait until all the leaves are down. Then they have you come and do 1 clean up. I will do weekly and 1 shot deals.
In the spring there is always branches fallen from storms, stubborn leaves that never wanted to fall down in the fall, and leaves that blow into the yard from other properties. So the property needs another clean up to look nice and get the lawns free of debris so they are ready to mow.
For me spring clean ups are done in March so mowing can start in April. Of course snow, and the grass staying dormant can delay the start of spring clean ups.