I will start doing all of my practice free hand sharpening with very fine grit stones. I will save blade steel while developing more ability at controlling my angle consistancy. The same thing would work when practicing using any system also.
I'm trying to improve my free hand skills so I need practice. Lots of practice. I wanted to lower the edge angle on my Sage4 free hand. So I spent about 3-4 hours using the Spyderco fine grit stone. If I would have started using a DMT fine or even coarse stone I could have completed the task in 30 minutes to an hour I think. But using a finer grit than I normally would have the amount of steel removed per stroke is MUCH less. So I got lots of practice trying to maintain a consistant angle. Also, by not starting with a coarser grit I reduce or eliminate the possibility of being done but having some of the coarser grit scratches left on the bevel. That's really a different issue but by using finer grit stones when time isn't an issue I know I won't have random deeper scratches. They bug me on edges that I want to look good for two reasons. First, the edge just doesn't look as good. Second, I know it was just a lack of patience on my part. I still have cheaper paring knives I like to use for practicing but when a nicer knife needs work I can spend the practice time on a knife I really care about without worrying about removing a lot of steel by using coarser stones AND the final finish could be better. I never thought about this before but many probably have. Just thought I'd mention it for anyone who is sharpens knives just for practice. I have sharpened very sharp knives just for practice. Just a thought.