Since the majority of my own Scottish ancestors are on my mother's side of the family, I've chosen to wear the tartans of those clans. The traditional "rules" of the tartans say one shouldn't wear one's mother's family tartans unless one shares one's mother's family name. But since my last name is Baldwin and is neither Scottish nor from my mother's side, I'm forced to do a little choosing when it comes to a family tartan.
My grandmother's paternal family are "Donaldsons," an English version of the Scottish "McDonald" which was created when my Great, Great, Great Grandfather, Thomas MacDonald married Elizabeth Tudor, a cousin to the Queen. Apparently it wasn't too cool for a royal to get hitched with a Scotsman, so Donaldson was used to fool the gossips, I suppose. Still, I'm made up of watered down MacDonald blood so I'm more than happy to wear the MacDonald family tartan.
A more pure Scottish bloodline comes from my grandmother's mother who was a Wallace. The Wallace family tartan is a fairly popular one and has both a dress kilt and a hunting kilt. Both Wallace tartans will be worn at times throughout the year.
No doubt there are other Scottish branches in my family tree but none are as prominent as the Wallace and MacDonald families so when you see me wearing a tartan kilt it will be representing one of these clans.