The Great Tartan Nonsense is highly amusing, and as you say it keeps the wee bairns in haggis . . . .
There IS a demonstrable pre-1745 connection with districts, rather than with particular clans, simply because local weavers had favorite patterns. So you often have a general association between the clan that is most populous in a district and the weavers' pet patterns in that district. From that you can have sort of a clan association, but it's pretty tenous.
I wear whatever tartan I like -- my dad's a MacGregor, my mom's a Glencoe MacDonald, but I think the MacGregor tartan's a little too garish for day wear so I wear the blue Hunting MacRae, just because I like the pattern. My husband's "official" tartan, Mar, is not only hideous (purple, magenta, and orange) but also only woven to order, so he wears Gordon. The mill owners still make plenty of money off us (although the better known setts are cheaper!)
Here's a Tartan Finder should you be so inclined . . .
self ping
I must admit, I do like the Baird tartan. Even if it was made up by some edwardian marketer. It’s a nice blue and green with a purple accent.