Ok, Teflon is the only one of those that can wear off over time, and it wears off into your food so consider that.
Stainless steel and cast iron are essentially indestructible and will give you the same performance on day one and 20 years later, if yours are acting different in such a short time frame they're either not stainless steel/cast iron or you're not taking proper care of them.
Stainless steel is almost impossible to ruin, unless you're cleaning them with industrial level sanding equipment I'm going to assume that's not the issue. However stainless steel is tricky to use, you need to preheat over MEDIUM-LOW heat until the pan is UNIFORMLY heated enough that it can levitate a large bead of water all over the surface. Then you need to coat it with some form of fat like cooking oil, and you need to WAIT for the oil to heat properly (just a few seconds, but it's not immediate). The words I capitalized are where I think most people make mistakes, they heat with high heat and so they have some parts that are very hot and others that aren't, then they put oil and immediately add the thing they're trying to cook, if the pan is not evenly hot enough cold spots can cause food to stick.
Cast iron is a different beast, they rely on a thin layer of polimerized oil to become non-stick. While this is resistant enough to survive most things it does wear down over time if you're not taking proper care of it. If your cast iron pan is not as non-stick as it used to be it needs to be seasoned, so do the following:
- Clean it thoroughly with water and dish soap
- Dry it well (I tend to put it over the fire again until it's dry, then you will let it cool down)
- Put a tiny amount of oil on it
- Grab a paper towel and spread it over the whole surface of the pan, it should look glossy
- Grab a new dry paper towel and dry the excess of oil, it will still look glossy but should not have any pools of drops of oil anywhere.
- Turn your oven to something like 200C/250C (it depends on the oil you used, look for seasoning temperature).
- Once the oven is hot you will put your pan upside down there and let it sit for at least one hour, but feel free to let it stay longer.
That should recreate the layer on the pan and make it good as new. You might need to do that periodically, maybe once a year or so depending on how you treat your pans. However after having the initial seasoning you can keep building it over time to avoid having to go through the whole process again. This is done by essentially taking good care of your pan, which means:
- Wash it after use (don't let it sink with water for hours). Contrary to popular belief you can use regular soap here.ñ, the advice is from an era where soap had much heavier chemicals.
- Dry it after wash (you can do so with a towel, I like to put it in the fire again to ensure its thoroughly dried)
- Apply a small layer of oil like you did for seasoning before putting it away.
If you do that every use it will be good as new indefinitely. If at some point you feel it's sticking or not acting as before you can resason it. Sometimes you might do wrong things like cutting stuff directly on the pan repitedly, or cook tomatoes or acidic food in it (the acid undoes some of the seasoning and leaves a metallic after-taste) which will require you to resason it, but as a general rule just cooking with it should keep increasing the petiquia (name of the coating created by the seasoning process).
Hope this helps, glad to answer anything else. I'm by no means an expert but I do like the few pans I have and like to cook so I've geeked over this for a while.