Winter is closing in fast. If you live in the northern part of the country, the sprinkler system should be winterized or at least should be done soon. Keeping up with leaves is the best way to ensure that there won't be any left on the ground through the winter. Do not leave them on the ground until spring!
The mower should be set a little lower than usual and there may be one or two more mowings left before winter sets in. Try and time the final mowing with mulching up the remaining leaves.
Once the lawn has been mowed for the final time, the mower should be winterized and stored out of the way. Your string trimmer should be winterized, and any other lawn tools should be cleaned up and put away in favor of snow shovels, ice melt, and other winter tools (again, depending on where you live).
Late fall fertilizing should be done after the grass stops growing but before the ground freezes. The timing varies depending on where you live and weather can be unpredictable but for my region (southern New England) it's around late November. Keep the spreader handy to spread sand or ice-melt come winter.