I bought a box of 500 heavy plastic knives - like you would eat with at a picnic - at Sam's Club. I use a Sharpie, write the name on the knife, put a piece of the clear Scotch tape on top. Don't use Magic tape, it won't last. This helps the sharpie stay nice and clear. Then, I bury it under the fans.
I have not had to use this method since I started using the AAA Engraved markers. They do not have a website, but here is their page on GardenWatchdog.
The stakes are so sturdy, and the tags are great. I have had some of the backer plates break, but I just put a little WD40 on the back, it loosens the glue, and then I use double sided tape to attach the label to a new backer.
I no longer map beds either, because using the AAA markers, they stay in place.
They are expensive. But, I had a major hybridizer here in my garden a few years ago... He made a comment on my less than average way of marking plants. He said - how can you spend $100 on a daylily and not spend $2 to give it a proper marker? Hmmmm - so I started buying them a few every year.