Pirl, your handwriting is beautiful on your beach stones, that looks very elegant but subdued. I use my stone/driftwood markers primarily for immature plants for their first season or two so I don't overlook them in the spring when they first emerge - the driftwood serves as a bit of a traffic cone (here I am) and the stone reminds me what to look for. In the case of the mints, I will likely keep them longer because I have planted several different varieties along the side of our barn and it is easy to mix them up.
I only use metal stake labels in my herb garden, primarily for visitors who want to know what all the different herbs are. I agree that they lend a bit of a graveyard look, especially over winter when things have died down. They also tend to get tangled in the weed-wacker when edging. Perhaps I'll redo the herbs with stones as well. Hmmm - winter project?