I've tried to poke around a bit before asking, so hopefully I'm not being terribly bothersome.

How do district tartans function? Google is telling me that the district tartans preceded the clan tartans; is that something I should look for? I found the Perthshire and Tiree tartan (and from what we gather it looks like Husband is from the Tiree), but I'm not sure if you're supposed to look at the ancestry for those or where you live now. Do people even wear those tartans regularly? Would it be a good idea to get him a kilt in that tartan as a present?