Thanks for the tip Tink on buying labelmaker tape on ebay...never thought of that and its so darn expensive at Office Supply stores.
Labeling is most important if you are hybridizing or if you plan to sell your plants. After many mishaps with labels - squirrels dig up the white plastic ones that stick in the ground, or husband "accidentally" removes when weeding, or they fade with the sun in a short time no matter what kind of permanent marker I've used, I went to the Ptouch label maker with white 1/2 inch weatherproof labels with black print. I tried the clear label with black print but I can never read them very well, especially on short markers that are down near the base of the plant.
I have bought the AAA engraved black markers on the metal stand, and I like these, but if you have very many cultivars (I use them on my hybrid roses as well), then it can get expensive. I like the Kincaid shiny stainless steel markers best. I print my own labels with the label maker and attach it to them - this is the least expensive, best way for me. I like the stainless steel much better than the eon zinc markers...its just more aesthetically pleasing.
As for size on the label makers, I use the middle size type - the large is too big and the small is too small. However, one mistake I made in the beginning was to set the size of the label I wanted - like 2". Put it on Auto and you'll be happy with how it turns out.