A combination of a proximal and distal taper are really a lot easier to produce if you forge your blade. Take the kuhkri pictured above. Starting out with a flat bar of steel slightly narrower than the finished blade, you would drive the steel into the bar to form the tip and the narrow part of the blade between the handle and the wide part of the blade. That steel has to go somewhere. Some of it will travel towards the tip, making it longer, and some will travel towards the handle, making it longer. Some will pile up and make the bar thicker leaving you with that section of the bar slightly thicker than the section ahead and behind it. There will naturally be some taper in both directions. The section from the thick point to the handle is called a proximal taper as it tapers towards the junction of the blade and the tang. The taper from the thick point toward to tip of the blade is called the distal taper as it tapers away from the junction of the blade and the tang. It would still be a distal taper if there were no proximal taper and the blade tapered away from the junction even as far back as the handle. Note: this description not only applies to the blade but to the tang as well. If the tang tapers away from the junction of the blade and the tang that too is called a distal taper. Not everyone puts a taper on their tangs. There is no reason that I can imagine to do a proximal taper on the tang. Even doing one on the blade is a special case.
The reason for that special case it to lighten the blade and leave mass out front to increase the force of a chopping blow. This bulge that was created in the bar could have been forged flat to eliminate the proximal taper and the distal taper would would be created from some point on the blade towards the tip. The farther back the taper is started the farther back the center of balance will be shifted. These are just elements of the blade design. They are not good or bad, right or wrong. They are just elements that may help the blade perform certain tasks at the expense of other characteristics.
To do a combination taper as above I would start out with a bar that is slightly thicker than what I would want the blade to be where it joins the handle. Lets say that I wanted the blade to be 3/16" at that point. I would start out with stock about 5/16" thick and lay out the profile and cut it out. I would then choose where I wanted the thickest part of the blade to be and put a proximal taper from there to the tang and a distal taper from there to the point. That is if you want to put in a combination taper. You could also choose some point along the blade and just do a distal taper from anywhere from where the handle would start to almost out to the tip of the blade. Just remember that the closer the taper starts to the handle the lighter and more responsive the blade will be but it will be at the cost of chopping ability. If you start the distal taper just a few inches behind the point it will be heavier and be less responsive in your hand but there will be more power in the chopping blow. Also, if you only want to do a distal taper, you would start out with a bar of steel the same thickness that you would want the blade to be at the handle.
Doug