This is arguably the hardest achievement to earn. There is no definite strategy for getting a creation featured besides making it creative, unique, and make it not look like an existing creature. The best tip at the moment is to look at the past featured creations and hope that they inspire you. Quality over quantity, but make sure your quality is quantitative.
It is advised that you are well known for your creations, as many people get more than one of their creations featured on the Spore website.
Getting an adventure featured in Galactic Adventures will not count toward this achievement. Instead, you will get Bestseller.
Between August 2011 and February 2015, this achievement was impossible to earn as the featured creations were no longer being updated.