What are some easy and relatively inexpensive ways to insulate the doors and windows in my house?

All the remedies below work. I use them all in my old home (102 years old). But if the air leaks are coming in from under the door and window trim, and not coming through the doors and windows themselves, the fix is a little harder but luckily, not too expensive. A hollow core outside door is hollow and other than putting a piece of Styrofoam over it, there is not much you can do other than replace it. With old windows the latch needs to pull it into a tighter fit to its frame. Check to see if they are working properly. You may need to scrape off some old paint to get them to fit. There is also a caulk available to seal around the window and its frame (Where it slides up and down) that can be pulled off if needed, and is made for stuff like this. (I use this on mine too). But, if the air is coming in from under the trim boards surrounding the doors and windows, the leak is between the door and window frames and the opening that was built to mount them in when the house was built. The (About 3/4 inch) gap between the house framing and the door and window frames is intentionally made larger to allow the doors and windows to be squared in the opening during construction. Shims are used as needed around that gap to get them square. all the room between the shims is normally left open. Especially in older homes when energy conservation was not considered. There are cans of spray foam available now that works well for getting into small spaces. I don't even know at this point if I'm in the right area for you. There are things to be careful of when using foam so let me know if you need this and I'll tell you what I can. Sorry this doesn't say much. Let me know what you are working on and I'll do what I can to help. Roger All the remedies below work. I use them all in my old home (102 years old). But if the air leaks are coming in from under the door and window trim, and not coming through the doors and windows themselves, the fix is a little harder but luckily, not too expensive. A hollow core outside door is hollow and other than putting a piece of Styrofoam over it, there is not much you can do other than replace it. With old windows the latch needs to pull it into a tighter fit to its frame. Check to see if they are working properly. You may need to scrape off some old paint to get them to fit. There is also a caulk available to seal around the window and its frame (Where it slides up and down) that can be pulled off if needed, and is made for stuff like this. (I use this on mine too). But, if the air is coming in from under the trim boards surrounding the doors and windows, the leak is between the door and window frames and the opening that was built to mount them in when the house was built. The (About 3/4 inch) gap between the house framing and the door and window frames is intentionally made larger to allow the doors and windows to be squared in the opening during construction. Shims are used as needed around that gap to get them square. all the room between the shims is normally left open. Especially in older homes when energy conservation was not considered. There are cans of spray foam available now that works well for getting into small spaces. I don't even know at this point if I'm in the right area for you. There are things to be careful of when using foam so let me know if you need this and I'll tell you what I can. Sorry this doesn't say much. Let me know what you are working on and I'll do what I can to help. Roger

I havn't gotten a response about the specific information you need. Let me know and I can help. Roger I havn't gotten a response about the specific information you need. Let me know and I can help. Roger