Nothing wrong with a good slim pair of raw or over the top distressed jeans (think Dior Homme) with a plain white shirt and a slim tie, as long as you don't wear your jeans up to your nipples, and wearing your tie in a 'casual' knot and stance is a must as well. It's not the most sartorially correct look, and has the potential to go very, very, very wrong most of the time, but I don't find it to be too difficult if for some reason I would feel compelled to wear a tie in a non-formal setting. WWFD? (What would Fuuma do?)