Whether you intend to install insulation yourself or hire a contractor, make sure that you know the guaranteed minimum R-value you are looking for. Have any contractor state that installed R-value as part of the bid. Also, prepare for the project by assessing what needs to be done to reduce air infiltration before installation. Include the cost of these added components and labor in your cost calculations. Keep in mind, too, that a tight home requires ventilation, so you may need to take another look at your bathroom and whole house ventilation strategies. Armed with all of this information, select the insulation that meets your energy efficiency, budgetary, and installation requirements. The end result will be a job well done, with energy and cost savings to tally long into the future.
If you have a room air conditioner, remove it for the winter or seal it up and insulate it. Water heater insulation jackets can work well for covering and insulating the air conditioner.