I'm now all caught up with this challenge (again!). I'm usually pretty good at keeping up, but it's been a busy month, polish wise!
In that spirit, of course I was stuck for inspiration. So I stamped. Over an untried though, so I'm still keeping that self-imposed aspect of the challenge up!
My base is the rather pretty Boots No7 Rose Truffle, and I stamped with Sally Hansen Fairy Teal and the Viva Mexico plate from Cheeky (I know Mexico isn't in South America, but I was stuck for what to do lol).