Step 1. Wash it really good in hot sudsy water. No need to scour, just get it good and clean. Rinse thoroughly with hot water.
Step 2. Dry it inside and out with a paper towel immediately and set on your range set on high. Smear veg oil (canola or soybean) or shortening and cover all surfaces inside and out with a thin layer of grease. Continue to heat on the range. It will begin to smoke.
Step 3. Take it outside to a charcoal or gas grill and let it "cook" on the grill for an hour or so.Heat should be medium to medium-low. There will be smoke, maybe a lot of smoke (that's why we do this outside on the grill.) This works best with the pan upside-down, to keep excess grease from pooling up and becoming a gunky mess. Aside: if doing an all day low-and-slow dish (pork butt, beef brisket, ribs) by indirect heat, that might be a good day to do your seasoning. That way you're not wasting an hours worth of fuel.
Step 4. Remove the skillet, wiping out excess grease and soot. You're skillet is now...ta-dah!...seasoned, and probably looks awful. It won't be black at all (unless covered in soot) but brownish and blotchy. But it will be seasoned. You can repeat this process, I suppose, but the best course of action is to use the pan...A LOT. The first week will be less than inspiring. Stuff will stick, but it will get better. Just scrub out after use with hot water and salt, dry, lightly oil, and heat on the stove until the oil smokes a little. Good luck! With use it becomes awesome, I promise.
I found this on the web and have been using it for several years with great results.
Clean your pan by rubbing the cooking area with a course salt, which acts like a brillo pad without leaving a residue
You season a cast iron pan by rubbing it with a relatively thin coat of neutral food-grade oil. Rub the oil off with paper towels or a cotton cloth. The pan will look like there is no oil left on the surface, but there is as the oil is just very thin. The pan may look dry, not glistening with oil.
Use vegetable oils (canola, sunflower, etc.), shortening (like Crisco) or lard for seasoning your cast iron pans (I use Crisco).
Place the cast iron pan, upside down, in the oven, with a sheet of aluminum foil on the bottom to catch any drips. Heat the pan for 60 minutes in a 500 degree F oven. Once done, let the pan cool to room temperature. Repeating this process several times is recommended as it will help create a stronger "seasoning" bond.
From then on, after using the pan, wipe it out with a clean paper towel. If there are a lot of burned on bits, clean with salt and reseason. If you have a lot of grease, you may use a little soapy water.
Research and practice over 25 years is summarized below. Works perfectly.
Materials needed for “seasoning” your pan: Crisco or palm oil, clean cotton rag, paper towels (don’t use vegetable oils as they tend to be sticky.)
1. Preheat the oven to 250F. for 15 minutes (it is imperative to preheat gas ovens to remove all moisture.) Place clean, uncoated item in the oven, set at 250F, and bring the item up to temp for 20 min. The pre-heat before applying Crisco or oil is essential to this process. Using an oven mitt, remove pre-heated item and set on a large baking sheet or newspapers (place hot pads under sheet to protect counter.)
2. Wipe on Crisco or palm oil with a clean rag, inside and out, and then wipe off all the excess with paper towels. Be careful not to leave particles from paper towel. Wipe it down until it looks like you've wiped it all off. Even if it looks dry, it's not. Very little coating is needed. If you TRY to leave a little bit on, then that’s too much. This prevents forming “splotches.” Now it won’t drip off so just put it right on your oven rack.
3. Return it to the oven, still at 250F, right side up on the oven rack, for 10 min.
Then, using an oven mitt, take pan out, wipe once more with folded up paper towel to remove excess oil. Return pan to the oven, and raise the temp to 300F. After another 10 min., take pan out, wipe inside once more with paper towel to remove excess oil. Return to oven, raise temp to 450F, and bake for one hour. Open a window as this produces some fumes.
4. After one hour at 450F just turn off the oven and leave it in, without opening the oven, to let it cool slowly for at least an hour.
5. Repeat steps 2 through 4 above four more times, but only apply Crisco or oil on the cooking surface. For the last time bake at 450F for 1 ½ hours (90 minutes) to set the finish. Let cool as in #4 above. Your cookware should be nearly black and not sticky. Your pan won't be sticky if the carbonization is complete.
The pan will gradually turn jet black and glossy after using it to cook foods. Be gentle with utensils until it develops a hard, slick black coating. Clean with hot water only - no soap or detergent. Avoid cooking bacon, ham, or anything with sugar until it develops a hard, slick black coating. The sugar in bacon and ham tends to stick to the pan until it has been used for awhile cooking other foods. (Frying potatoes is excellent for this.)
Can you be a bit more specific? Otherwise, it will be difficult to guess exactly what went wrong. Is it because the oil turned gummy? Is it because the oil turned to hard charcoal solid bits? Is it because the seasoning initially looked fine, but it peeled off and won't last? Is it because the seasoning looked and felt great, but it did not provide a nonstick surface for cooking?... etc What were the problems?
I understanding that it can be frustrating for new cast iron seasoning. Yet, it will be more effective if you can describe the symptoms. I mean, if you are going to a doctor, you want to say more than just "I don't feel good".
This is the technique I use. It is labor intensive however.
That said, she focuses on two principles that apply no matter what oil you're using: many very light coats, and hot enough to polymerize the oil. Safflower oil has a pretty low smoke point so if flax oil is out of your budget, give it a try.