You need to make sure your chimney pipes are in good shape and are functioning properly this year. Most people don't think about the chimney pipes when they are worried about heating the house but they are very important. The same certainly can be said about stove pipe if you have a wood stove or gas wood stove. The stove pipe is what connects the stove to the chimney pipe BTW.
While we are talking about chimneys, make sure your chimney caps are of good quality and great working order because without this, it can be dangerous, not to mention, inefficient. Lastly, if you have a masonry chimney you will want to check out your chimney liners to make sure they can help you during the cold winter. They are important in heating efficiency and efficacy.