Onto the rail connecting hardware. I know there are hook systems available, but I've never been comfortable with the stability of those. I've been a longtime fan of bed bolts, but don't like the need for them to go all the way through the leg of the headboard. I got around that restriction in the past by making faux through tenons to cap them off, but I wanted to keep the clean look of this leg. I'm going with a system that is essentially a threaded rod secured into the head/footboard which is secured by a bolt in the rails. Here you can see where I've marked out the slot for the bolt/washer and I've already made the hole for the rod to slide into.