I have been having good results by skipping the preparation all
together and using Bull's Eye premixed shellac from home depot. It
comes in either clear or honey, and they also sell a spray version
(which I don't use). The shellac is thin enough that it can be applied
straight out of the can, yet it can be thinned with denatured alcohol
for a softer finish. I just finished an end table project where the
table top is a 2" thick endgrain slice of some unidentified relatively
durable softwood. The top is finished with between 6 and 8 coats of
this shellac (I lost count around 5 coats). So far it has worked
beautifully.