sybred: there's no particular time to use hammer & chisel. it's just a technique that differs from push graving, or using power assisted engraving. doing hammer work can be inexpensive. the main requirement is a good solid vise that is set upon a sturdy pillar, post, or support.
as a technique, i think it requires a lot less time to become proficient, than does push graving. it is also way less expensive to start h & c work, than power assisted engraving. i invite you to look thru the tips section to familiarize yourself with the many things you'll want to learn. be advised, some of the finest engraving done today, is done with the hammer and a set of chisels.
thanks for joining, and good luck in your pursuits.
You tube videos. The one by Sam shows how beautifully it can be done. A solid vise, good sharpening and hammer and chisel and try it on.
The sharp chisel is imperitave...it makes sure that the chisel cuts and doesn't skitter and scratch.