A toe ring is a wonderful and thoughtful gift.
I have never done that, but one Mistress I knew a decade ago had her eyes on a strappy backless open-toed pair of leopard high heels. I bought it and it matched her leopard bikini and my homemade Tarzan thong which made for a wonderful "Tarzan/Amazon Queen" session. She had lovely feet and I worshipped them endlessly when allowed. Never did like to worship shoes, boots or feet with stockings. Bare feet? Oh yeah...
Another gift, if you call it that, was a Mistress had clear, backless and open toed high heels. She wanted to wear them for a session of ours but couldn't. I asked if I could try to fix them and with a little Gorilla glue I became a hero. I LOVE backless high heels and the sound they make when the heel hits a hard floor and sometimes, when women don't wear stockings, you get a double echo because the instep gets caught a bit on her slightly perspired foot. Mmmmm.... (LOL!)