I learned how to etch copper several years ago and went through a period of non-stop etching. That wore off and I have not used my etching supplies since. When I woke up this morning, I felt like etching! I dug out the supplies: ferric chloride, heating pad, plastic peanut butter jar, wire for suspending the pieces, resist (nail polish, sharpies, etc.), copper shapes, antiquing solution, yada, yada, yada.
I drew my patterns and words with fine-tipped specialty nail polish -- I think these tubes are designed for people who draw detailed designs on actual nails. I also found a pack of Chartpak letters that I know make a good resist also. They need to be burnished onto the surface of the copper very well. I covered the sides and back of the pieces with Sharpie so those places would resist the etching process.
I suspended the pieces in the ferric chloride (in the peanut butter jar) and placed it on the heating pad set to medium. This is not absolutely necessary, but heat speeds up the process. After an hour, I pulled the pieces to check the etch depth. It was good!
Next, I removed all the nail polish and smoothed the rough edges. Now the pieces were ready to be antiqued. I think they came out great!
... except where the nail polish was applied too thickly at the start of the word memory here: