Pressure-washing doors and windows can be an excellent way to discover drafts around your windows and doors. I should provide some backstory here: Springtime in Atlanta, Georgia can be absolutely beautiful. There are flowering trees — cherry, peach, pear, plum, and dogwood — simply everywhere. This, of course, causes its own problems. Allergy experts consider any pollen count in excess of 120 to be extremely high. (A pollen count measures the number of pollen particles detected in a cubic meter of air over a 24-hour period.) Here in Atlanta, we see pollen counts in excess of 3,000 on a daily basis during the months of March and April. Do you remember how Reagan once claimed that trees cause pollution? Well, here in Atlanta, they do — particulate pollution. 
Each individual pollen grain is microscropic in size, but when you have a few billion floating through through the air around your house, they leave a thick yellow dusting over everything. Add some April showers and this turns into a sticky yellow scum that the rains won't wash away. Once the flowers are off the trees, generally around mid-April, we all take a deep breath — without sneezing, for the first time in a while — and start the cleanup. 
Our deck is usually reddish-brown but was mostly yellow yesterday when I started pressure-washing it. An hour later, the deck was once again the correct color. Once the deck furniture was pollen-free, I then washed off the window sills and door jambs along the back of the house, put away all of the gear, and walked back inside — where I promptly stepped into a puddle inside the back door.
So here's the tip: Get the hose or a pressure-washing rig and spray down your windows and doors. Any gap in the weatherstripping around your windows and doors that will let water in will also let air out as well. I have now added two doors and one window to my list of home energy saving projects.