Since my name was mentioned in the original post, I'll respond to how I do it. That is in no way saying it's the correct way, just "MY" way.
I use one pint mason jars that I buy at the grocery store. You can buy a case (12) of empty ones with the lids for just a few dollars. I put a strip of painters tape down the side vertically and using a ruler mark off inch marks up from the bottom to the top. (about 4" actually) When I mix the shellac and alcohol 50%, I just pour in 1" of shellac and then 1" of alcohol and stir. To apply the finish to the project I use a brush or rag. I have and do use the foam brushes at times but the alcohol will dissolve the foam and leave pieces of foam after a short while so be careful and toss the brush when you start to see it expand and fall apart.
The nice thing about the mixture is that the alcohol is a solvent for the shellac so it makes for easy clean up when you are finished with a bristle brush or to clean your fingers. I have an extra jar of alcohol just for clean up. Be sure and use a piece of tape on the lid of the jar to mark what mixture is in it.
Warning! Do not leave the mixture sit in an open container for very long. The alcohol will evaporate fairly fast, draw water into the mixture and, not to mention that it could be a fire hazard!
For my "Rude and Crude" finish, I Pour in 1" of BLO, 1" of mineral spirits and 2" of polyurethane. Mix well and use a brush to apply. I do use a foam brush with this mixture as there is no alcohol in it, and use a jar of mineral spirits for clean up. I have had very good luck with this mixture for popping the grain and a final finish all in one!
Warning! Wrap the threads of the jar with a lap or two of teflon tape as the mixture will seal the jar so tight that it can't be opened easily. I sometimes have to wrap a leather belt around the jar to hold it so that I can unscrew the lid.
I like both of these finishes because they are simple, easy to apply, dry fast and usually come out "Lookingood!" for clear, natural wood looking finishes.
Rog
PS... Yes, I buy alcohol by the gallon!