For your forge project, first you want to make some charcoal. Soft wood like pine makes faster charcoal than hard wood. Ideally, you could stuff a 55-gallon barrel with the wood, punch holes in the lid for gases to escape, and light a fire underneath it. After a while smoke will start to come out the holes in the lid. When it quits smoking, your charcoal is done.
Obviously, 55-gallon metal barrels aren't likely to be handy in the wilderness. For our class he used a small campfire burned down to coals. He mixed sand and mud to make clay. Here, Robin is mixing the clay in a bucket while Jason explains the procedure:
Then Jason made a horseshoe-shaped bowl on the ground, about 18" long and 12" across:
Then he improvised a bellows with a trash bag. He said you can use things like clothing, stuff bags, anything that will hold air, even if it's not air tight. He had found a leg bone from a cow in a nearby field, and he used a stick in a hand-drill fashion to get the marrow out, creating a tube. The tube can be made out of anything hollow: bone, reed, pipe, whatever you can find or make.
He took the garbage bag and cut a hole on one bottom corner and attached that over the end of the cow bone tube. He used duct tape, but you could tie it with cord if you didn't happen to find duct tape while scavenging the wilds (or didn't have some in your pack). The other bottom corner was available to be weighted down with a foot or a rock so it wouldn't blow or twist. If you have an extra person available they can be your bellows person, but the whole procedure can be done by only one person:
Next Jason dug a rench through one side of the mud horseshoe and buried the other end of the cow bone so the opening was near the bottom of the fire bowl. The coals from the campfire were scooped into the bowl. He laid a piece of scrap metal, in this case, rebar, in the fire. A volunteer from the class worked the bellows by scooping air with the garbage bag, holding it closed with his hands, and squeezing it to force the air through the cow bone. The air rushed onto the coals and made them super-hot. Heat rises, so you want to keep your metal above the heat, not shoved down into it.
Now you need somehting to hit on, and something to hit with. To hit "on", find a rock, cement, or anything hard and not flammable. To hit with, use a rock, or hammer if you have one. (This is also something a person can do in their backyard where you might have all kinds of things available.)
If you're using a chisel, say, to "cut" a heated piece of metal, such as a lawn mower blade or rebar, dip it in water between blows to keep it cool and hardened. Here Jason is using a chisel to cut a heated piece of metal:
When making something long, like a sword (katana) work only 2" at a time, since that's all you can properly heat at a time. You can hammer a knife blade out of clay first to get a feel for it so you don't waste a lot of steel.
Work at the far edge of your anvil so the hammer won't hit the anvil instead of the metal you're working and cause an uneven surface.
You can use a bellows for cooking. He said water will boil in less than 3 minutes. In the Gobi desert there isn't wood for fires, so they cook over horse manure. They carry a portable bellows so their food cooks faster.
Other tidbits: The Japanese folded steel to work the impurities out of it. They actually were making steel, not forging it. Also, he said some railroad spikes are made of iron and can't be worked on a forge. In fact, if you overwork your steel, pounding on it too much, you'll make it into iron.