Wow, you need to do this. It's cheaper than anything you can buy, just as good or better because of the varieties of spices that can be added and it's really easy.
I got a flank steak and cut it up into thin pieces (across and/or with the grain) and trimmed all the fat. It's really important to trim ALL the fat. It looks gross in the finished product and it does NOT render out. I think I'll be choosing a less marbled cut next time like a top or bottom round. And, cut it thin. The more plump pieces don't have a good mouthfeel when eating them.
Take the trimmed pieces and marinate in a bag. I used 1/3 soy, 1/3 worcesteshire and 1/3 mirin for about 4 hours. I removed them pieces and lay them on the depicted cooling rack. This was placed on top of a roasting pan and placed on a low-setting hotplate. I adjusted the temperature on the hotplate so the air above the rack was about 90-120, hotplates have sloppy cycling. I gave the pieces a final sprinkle of coarse salt and went about my way for a day. No fancy airflow, just relied on convection. A day later, jerky bliss. We all liked it immediately. It is Scoopy's favorite!