How to take care of the teflon coated cookware to ensure their long life?

Be very careful heating it

Usually with a steel or iron pan I'll crank the heat under it and go do something else for a couple of minutes while it gets up to temperature. If it takes me five minutes to get back to it, maybe it's a little too hot and I have to hold it away from the burner for a few seconds before adding the oil. With teflon, that can damage the pan, so I keep a closer eye on it and hold my hand over the pan more often to see if its ready.

Make sure food doesn't stay in the very bottom part for long enough to burn on. The flared sides and narrow bottom of these pans tend to concentrate heat at the bottom, and burn on food more easily than flat-bottom saucepans and frying pans. Once food is burned on, there is no way to scrub it off without also removing the nonstick coating. It only takes one batch of fried rice or browned onions to permanently wreck the pan. Finally, stir-frying involves a lot of vigorous motion with utensils, which rapidly wears out nonstick layers. With nonstick woks, it is simply a matter of time before they are ruined.

My suggestion is to replace your teflon wok and kadhai with (respectively) carbon steel and cast-iron equivalents at the earliest convenience. Woks and kadhais are designed for high-flame cooking, and if you reduce the heat to protect cookware, then the food won't get browned fully. With these materials you can use full heat without ruining pans or releasing toxic chemicals (from overheated Teflon). Cleanup is simple: just rinse out, scrape off burnt bits, wipe them down with a paper towel, and season with oil.

Finally, wooden or silicone rubber utensils are the best for a nonstick wok or kadhai; they won't scrape off the nonstick layer unless used very roughly, andthey can stand the heat without melting. Normal plastics (particularly polyethylene or polypropylene) tend to melt, and metal will scrape up the nonstick coating.

Totally agree with BobMcGee. I replaced most of cookware with steel and cast-iron ones... Except the ones that I use for pancakes/cakes or similiar stuff that take short time to cook and don’t need too much heat. Even then;
- I use wooden spatula/spoon.
- I clean pan with paper towel & change oil after each piece/bunch (in case of burnt stuff/oil – which harm pans as well as health).
- To avoid scratching in the cabinet, I never put any other material in/on teflon cookware (either hang up the pans or put a soft metarial in between).

Don't leave them full of water for a day or two in your sink because you're too lazy/busy to wash them at the right time.

Happened twice, had to convert my pans in flower pots: they formed some "bubbles" under the teflon coating, and, while cooking and stirring, these bubbles popped and the coating went out and ruined my food...