First of all, be sure your lawn is cleared of any leaves and grass clippings. This will allow more exposure to winter moisture and light. The lawn should have been fertilized for the last time by now with a pound or so of nitrogen, with some portion of that being in a slow release form. Also, mow for the last time, leaving the height a little longer than a normal cut. This will allow for more leaf surface for photosynthesis to continue. Weeds should have been treated by now, particularly perennial weeds for next season. While very little is happening from a pest standpoint, the most important thing is to monitor all trees, shrubs and lawn areas for soil moisture. If snow or rain has been absent, a deep thorough soaking of landscape areas once every two to three weeks will help maintain plant health.