I have a big selection of cast iron pans – one of which I received from my stepfather in 1957 and have been cooking in ever since. Its inner surface is so slick the cornbread lifts out easily and even fried eggs slide across the bottom with a flick of the handle.
Over the years I’ve bought many different cast iron pans; some pre-seasoned and some rusted and pitted from neglect. With the latter I usually use sandpaper to buff out the rust, then scrub it with soap, and then see how smooth a plastic scrubbie will make it. After that I swab the interior with vegetable oil and put the pan in the oven for a couple of hours. Some where in that time I wipe down any drips and turn the pan upside down for the last time.
My tendency is once the first go-round is done to use the pan as much as possible; fry eggs, French toast, chicken, fish, whatever process uses a bit of oil and doesn’t leave too much crispy bits.. I don’t wash the pan between uses; just scrape out any bits and wipe it thoroughly with paper towel and use it over and over till its cured. In the picture you will see some carbon steel pans that I bought last year. They too have to be cured and they are shaping up nicely with repeated use.
I do not use my cast iron for acid stuff; tomato sauce or milky stews. For those I use stainless steel.
One recommendation that I have not had the chance to try yet appeared in the January/February issue of Cook’s Illustrated (pg. 30). Developed by Sheryl Canter it uses flaxseed oil and reportedly creates a rich, slippery, finish that can withstand even the dishwasher! Here’s a link to her blog- http://sherylcanter.com/wordpress/2010/01/a-science-based-technique-for-seasoning-cast-iron/