Do you start with the Zero Filter first.?
What are you looking for in that first test strip.?
Thank You
Well, I am me, but I don't know if I'm going to be much help here. You see, I proof all my negatives either on graded paper or with a grade 2 or equivalent filtration. I then extrapolate a starting contrast grade from evaluating the proof and just dial in the anticipated correct filtration (it's rarely exactly correct, but a close starting point). In other words, for the first test strips I don't use split-grade printing at all. It's really just habit based on my years of printing on graded paper. What I've done with VC paper is to take advantage of the possibility to give different areas of the print contrast tweaks using split-grade techniques.
I first make a test strip at my extrapolated beginning contrast and find the desired starting exposure based on a (hopefully well-chosen) highlight value. Sometimes I'll adjust contrast filtration too at this point, but rarely. I then make a straight print at the determined exposure. After evaluating, I'll decide if I want to change exposure or filtration or tweak contrast using a split-grade technique.
So lets say I've got an initial print that needs a touch more exposure and is a bit weak in the shadows and also has one underexposed highlight area. At this point, I may just change basic filtration and make another test strip. Or, alternately for example, I'll add a certain percentage of exposure at the filtration I'm using and then give, say, 20% extra exposure with the hardest filter (either all the M I can get on the color head, or I switch to white light and use a Wratten #47B filter under the lens). Then, I'll dial all the way to soft, or use the Wratten #58 under the lens and burn the underexposed highlight area for whatever percentage I think might work.
I'll develop the print, hang it on my white board and evaluate it with notebook in hand and make a plan for the next print. Usually by print four or five I'm closing in pretty well on my desired result.
My split-printing is limited mostly to dodging and burning with hard/soft filtration while the "basic" contrast is an intermediate filtration. I find it easy with my set-up to just switch the color head to "white" light and use below lens filters for the dodging and burning. I'll use the hard filter to set a shadow and to get some detail in a highlight that I don't want to grey down too much. I'll use the soft filtration to bring in underexposed areas or tame too-light highlight details. Sometimes I use both in one area. I also dodge and burn with the basic filtration a lot (especially edge burns).
I don't know how much all of the above will help you if you want to use a split-grade printing regime for everything from start to finish using only soft and hard filtration. However, the theory is fairly straightforward. You need a combination of soft and hard that gives you some desired intermediate contrast grade. Let's say you're aiming at grade 2.5 contrast equivalent (I still find it easiest to think in terms of grades... at least that way I have some road signs in the contrast spectrum). So, you test for that, or simply start with equal amounts of hard and soft filtration. In the "Darkroom Dave" video linked to above, he starts with a 2.5 filter for the test strip, finds an initial exposure and then splits the exposure between hard and soft. One could, however, make a chessboard-like test strip with soft filtration in varying amounts on one axis and hard filtration on the other with the 50-50 split in the middle. Or make a soft (or hard) test strip, find an exposure for highlight (shadow) and then make a second test strip with the basic exposure from the first test and varying exposure from the hard (soft) filter. Whatever works and seems easiest for you. And, it doesn't make any difference which filter you start with.
Since I have a pretty good idea where my target overall contrast will fall from the proofs, I find it easiest to guesstimate a starting filtration and work from there.
Best,
Doremus