Brad, to answer your question (and then some):
Warning, the following post is not machining related and will bore most people to tears
If it is something very simple and I have a picture of what I'm going to do in my mind I'll just go directly to the computer and do it. A basic machete for a weekend chore for example. In that case I didn't use a fixture, but just clamped some A2 between two vices and cut my profile with a 1/8" cutter, taking care not to cut it out all the way, but leave .010" at the bottom around the edge and pop it out by hand (the burr gets cut off later anyway). Then it goes edge up and gets "sharpened" in the mill before grinding. In that case from sitting down to start and cutting chips takes about 30 min, mostly mill setup. While it is cutting the profile I'll program the edge cut, so that starts as soon as the profile cut is done. So it is in HT pretty soon after I decide I need a machete.
Something like this skinning knife is different. I designed it for the way I process a deer. I like my venison tasty, tender and well aged, which means I like it rare and not gamey. Every hunter has different opinions, but to me the best venison is very clean, which allows you to eat it safely while still pretty rare. So the way you process it is important. To start, I generally take a head shot if given the opportunity, to avoid disturbing anything in the body cavity and to prevent a long run, and tracking it. Also, I don't field dress a deer, I put it on a tractor and get it up to my skinning area pretty quickly where I process it the way my step father taught me (and the way a farmer taught him to butcher pigs). I skin it down leaving a little around the genitals and anus. I pull that out a short ways and tie that stuff off. That way there is no danger of feces or urine contaminating anything. Then I open it up a little bit taking care not to cut anything I don't mean to. I don't split the pelvis like most folks. I do reach up in and disconnect all the stuff connecting the reproductive and excretory stuff to the pelvis, then pull that stuff down. Then I finish opening it up and let all that stuff fall into a chum bucket under the deer. Sometimes I'll split the ribcage, sometimes I won't. I won't go into more detail because I've found that some people get squeamish (and would prefer not to contemplate where meat comes from, which is their prerogative) but the tools you use dictate to some extent how smoothly this all goes. When I'm done I have a neat clean carcass without nicks and without bacteria in the meat. Nicks through the fascia can introduce bacteria into the meat, leading to smells and unhealthy food (if eaten rare).
All of this is where knife design comes in. My old buck clip point was too long and the clip point tip nicked meat. Another popular shape is kind of leaf shaped and short with a gut hook. That doesn't nick meat so bad, but it doesn't fit up into the pelvis or handle well either. An area with belly is important, but you don't need much, and making the blade that fat for skinning? If you're skinning by carving with that giant belly, you're doing it wrong...
I personally think gut hooks are inelegant. I think their often ugly, when they bunch up they can get hair on the meat, they weaken the blade and a blade that fat handles poorly (for me) and they're unnecessary. With about one deer of skinning experience a hunter using a drop point design, with the edge out, can unzip a deer fast, exactly where you want it, and without nicking anything. You lay it flat against the deer and control the depth of cut with the angle. Once the hide gets started over the edge it stays there during the cut. It is just my personal opinion here.
For the way I process a deer I need something with moderate length, a narrow tip with a good belly at the very end. The handle needs to allow me to put the bottom into the palm of my hand and extend the blade out like an addition to my index finger. D2 doesn't rust much and holds up to hide and a thin hollow grind makes shallow cuts in flesh better than anything. I never dangle a *sharp* knife off my wrist or anything else, so a lanyard hole is of no use to me, I just set it down next to the bone saw on a table. I need a decent index finger indent or a guard, because hands get slippery, and I like my skinner sharp like a scalpel. Those requirements drove this design.
So, there you have the thought process behind the knife design. For something like that, I draw it out several times. Come back to it later and tweak it again. Sometimes I can't decide what I want unless I see it, so I draw quite a bit. When I have what I think I want I scan the drawing into the computer on a regular old flat bed scanner. I bring it into photoshop and adjust the angle to be level and crop it tight against the design. I create a feature in the CAD system the basic size of the blade. I import the jpg image into the CAD system and position and scale it until it fits that basic scaling feature (generally just a square). Once it is correct I trace it with nurb splines, using as few control points as possible to prevent weird undulations. This tends to iron out waviness and help keep a sleek elegant shape, while still being true to the design intent. Then I save the file and start playing around with the proportions a bit, trying slightly different angles etc until it is as perfect as I can make it. Then I "grind" it in the system, playing with all of the variations there. Then I do the scales. I'm sure it takes me longer to design a knife this way than it would take me to just sit down and grind one, but I like to think the extra attention given to the design shows.
But this is getting seriously long winded and some serious thread drift, and I'm sure you folks looking for cool shop stuff are bored, so I'll get back to the good stuff and weird techniques tomorrow.
:thumbup:
, that of which, I just can't seem to come up with at the moment 
