The clip on tie is incase a crazy pax attacks and tries to strangle you because of a delay As for ties, I know how to do one up as I wear one at work but I wouldn't go as far as to wear one on the plane!

Personally, I prefer to travel in jeans but feel like I haven't made that much of an effort. Basically I have seen jeans seem to be OK for domestic US airlines, but will somtimes preclude you from upgrade. I now know I can get upgraded on DL with them, WN one can't get upgraded, and on AA that upgrade list is always full and I am always like 20th standby anyways, so jeans it is!!