Place 50 decorations anywhere in the game, ranging from fences, leaves, chips, chairs, and more. You can get this achievement by placing the same decoration 50 times. The easiest way to get this achievement is to buy 50 Small Fence. This method will only cost you 2,000 acorns total and they are the cheapest decoration to buy in the store.
Note: This achievement is not glitched, but upon unlocking this achievement, or putting 50 decorations on the map, the game will start to glitch. You will get random black screens; to stop this from happening after you place 50 decorations, simply delete them off the map. You can delete decorations by tapping on the item, and the hitting the purple box above it. You will not be refunded any acorns if you delete an item from your village.