Step 1: What I Used

Most of what I used to make this branding iron I just had hanging around my garage, so here is the list of what I found.
Bench vise
Thick soft jaws (not vital but do help a bit)
Long nose pliers
Mole grips
Cold chisel (only needed for angles, flat head screwdriver would suffice)
2 pieces of 4mm stainless steel rod (to make jig)
2 peices of flat steel bar
Soft steel flat bar 1x10x750mm (only peice used as the branding iron)
If you don't have the same metal as i used you could use almost anything else, provided that it's metal, easily bent and retains it's shape in high temp. (If you have a choice of metal, I would opt for steel over aluminium or copper because it retains heat much better)

Step 2: Design

It may not seem like it but it is important that you draw out a design of what you want the iron to look like and make sure that it is possible to do with the one piece of steel (unless you want to do some brazing/welding (not soldering, it would come apart)) without it crossing over). it is not important, however, to follow your design exactly. Infact the only part that I paid close attention to was the P, I wouldn't have been able to do the rest to scale. As can be seen, I also did'nt think of putting the border around the design until I'd finished the rest. It makes it look alot better in my opinion.

Step 3: Making the Jig

I found that using this jig made it a lot easier to make curves than trying to bend the metal with both pliers and free hand around things. it offers a surprising amount of control and it's very simple to make.
Take the two lengths of steel rod and put them in the vise next to each other, loosely. Insert the material to be bent, wiggle it around a tiny bit then tighten the vise.
This way, one rod acts as a former, the other as an anchor.

Step 4: Start the Iron

Begin to bend the chosen material by any means neccesary to meet you design shape.
I mainly used the jig because it is so easy. the rod only has a small diameter so I needed to bend only slightly then move on a bit and bend again to make larger radiused shapes.

To do a 180degree turn I used the jig and made the length a little shorter than i wanted it, then took the mole grips and squeezed hard. if I had had a larger pair of pliers i probably would have used them instead.

To make a sharp turn what I did was: bend it 180degrees, put it in the vise carefully and with the chisel bend it back to the desired angle.

To make closed rings, whati did was to close the ring as much as possible with the jig and then pulled it in the rest with long nose pliers. With small loops (eg. on the K) I formed with the jig and with the metal still raound it, pulled in with the pliers. This way the loop would't deform.

Every so often the iron should be straigtened out by putting it between the two flat bars in the vise (without the bars, it may not straighten out well, and will leave a texture on the iron). I did this often so that when done at the end, the iron wouldn't deform beyond regognition.It's important to do this at the end so that it will contact all of the meat.

To undo inevitable mistakes, view the next page.

Step 5: Repair Mistakes

It is very easy to mistakes with things like this, most of these are minor and just need tweaking but others need compelty redoing. When I made mistakes like this I unraveled it with the chisel (or screwdriver) and then pressed it between the 2 flat bars in the vise. Very easy to undo and almost like the metal was unused at that point. If done repeatedly in the same place, it will go weak and eventually break off.

Step 6: WOW Your Friends

On my branding iron I just left a bit of metal sticking out of the side to pick it up with pliers or whatever else, but would be better to put proper handle on top.
To heat up the branding iron either bury your it in coals or hold over a burner for a few minutes. (Coals are better, more even heat).
When it's hot enough, take it out, place on that steak and press down until your happy about the mark it's left.

Happy branding.