Re: the OP
Like you, I am relatively new to the craft and am using the Eco-flo products almost exclusively. Mind you, I am searching fairly frantically for other methods to get better control over the process, as the idea of using water soluble products to color leather makes me cringe a little for some reason. Still, I've had some good results with a little experimentation.
For what I am trying to achieve (fairly antiqued appearance) it's been necessary to apply several coats of the color STAIN, more or less as they describe, followed by a short drying period after which I selectively modify the tone using a SLIGHTLY damp sponge and soft cloth or paper towel. That varies somewhat from the instructions provided by Tandy, but it works for me. It usually takes 2 or more applications for the effects I have been after and the short (5 minutes or longer) drying time has seemed essential to prevent too much inadvertent loss of pigmentation when I go back over the piece to remove excesses. I'm absolutely NOT trying to produce a perfectly uniform pigmentation over the piece!
The Eco-Flo antiquing gel or "cosmic snot" has been a real PITA. To simply apply it over the stain and rub as in the video simply produces a streaky snotballed mess for me! Once again, the solution has been to throw on a heavy opaque coat, let it dry thoroughly and remove selectively, allowing it to dry thoroughly before sealing. The results thusfar have been described as "incredible" by relatively dispassionate observers. (Of course, it may have been their astonishment that "I" managed to create anything even halfway decent in appearance. lol) The results have been quite gratifying, if slow to materialize.
All other methods tried have resulted in pure frustration, with the exception of the Eco-Flo dye, which gave a fine result and Fiebings USMC Black dye which has been OUTSTANDING! Too bad I am into producing intricate work that benefits from color contrast. If I wanted solid colors, I would go Fiebings all the way based on experience thusfar.
Incidentally, you will need to use the stain if you want to manupulate contrast if I am not mistaken. Rereading your post I saw you are using the dye. It doesn't seem possible to change that much after it goes on.
I'm relatively new to the craft and should probably just keep my mouth shut and read, but we have a similar interest in regards to finish and seeing as how I simply try things to see what happens, I may be able to help a tiny bit. I've inadevertently produced a similar effect to photo 1 using Eco-Flo stain, applied unevenly via the edge of a sponge using a dabbing action & removed with damp cloth. I looked upon it at the time as a fault because it was not what I intended. At this point, and due to your post, I can see how it might be useful. If you try the theory, then I can tell you that Eco-Flo briar brown is too warm to reproduce that tone but it looks like the coffee brown might possibly work. I'll have to go back & experiment with it myself. I'm not sure on the other 2. Photo 2 looks like normal patina from the flexing of wear. And I am suspecting that photo 3 may be reproducable by flexing the piece viciously before staining. I'll try that before it is over to see if I can make use of it. I'm partial to nice leather grain. Anyway, I hope that is of some use.