A basic bench hook is no more than a mini-shelf on top of the workbench, sporting a rear fence to press a workpiece against while you saw a cut line. One lip below, which holds it in place, and one lip at the back above, where you press the workpiece to hold it in place firmly while sawing.
This one is a bit more elaborate. It is not my own design, and I no longer have the magazine where some enterprising woodworker published it as a tip many years ago. If he's out there, I hope he'll step up and claim authorship of his design, because I've appreciated his innovative thinking for a long time.
Here is the basic bench hook, with storage for four dowel pegs on the left, and a drop-shelf to prevent cutting through the bench hook after doing 90% of the cut on a workpiece.
The final chore is to drill some random holes 1/2" deep in the bench hook that loosely fit your selected dowels, stored above in equally dimensioned holes when not needed. The dowels serve to steady oddly-shaped pieces for either sawing or drilling. When attaching lathe face plates for turning, for example, the drill produces a great deal of torque and the workpiece is nearly impossible to hold by hand with any stability. When secured in a front vise, this bench hook and dowel set up makes it a one-handed operation.
So, knowing I cannot improve on this bench hook design, I'm ready to put together a new one. Truth is, I'm not going to throw away the old one, but save it for more 'scrappy' uses like chopping end cuts and various dent-worthy chisel pounding.
I hope this is of some use to others. For construction, here is one more photo of it on its side to clarify my directions. The dimensions are entirely up to you, so make it to fit your bench, or alter it as needed. I really wouldn't know how to get along without it!
Addendum: mine is only one kind of bench hook. Here is a YouTube link to another kind by famed handtool officionado Roy Underhill: