Complex sentence: More recently belt buckles have become a popular fashion accessory, giving rise to a new style known simply as the "front tuck," tucking in one's shirt in an attempt to show off the belt buckle.
Split into simpler sentences: More recently belt buckles have become a must have fashion accessory, it has even given rise to a new form of tucking in ones shirt known simply as the "front tuck". The front tuck is just as it sounds: the front of the shirt is tucked in an attempt to show off the belt buckle.