OK, I am mentally planning for my daughters wedding in July and have a question on the fly plaid. Various photos I have seen show it either going over or under the shoulder "flap" (can't think of the correct term right now). Is there a more "correct" way or is it a user preference?

The coat I will be wearing is an Argyle (see thread: http://www.xmarksthescot.com/forum/f108/revealed-59655/), I don't care for the PC, that is why I went with this one and the fly plaid is about 46" long, made of 10 oz wool.

Any help and/or photos would be helpful.