1. Men Wear Kilts (NOT skirts) — I learned first hand that you never tell a Scottish man that he has a "nice skirt". Apparently the difference between a kilt and a skirt in Scotland is that underwear is never worn under a kilt, and the men I've met at weddings are more than happy to prove that to you (especially after a few scotches). On another note, don't compliment ANYONE on their pants...
2. Women Don't Make Speeches — Traditionally only the father of the bride, the best man, and the groom make speeches at the reception. Our North American tradition of showing slideshows and videos at weddings has not made it into Scottish weddings yet either.
3. The MC or Host Is Usually An Employee of The Venue — Instead of getting your best friend, sister, or cousin to MC the event, the venues at Scottish weddings usually supply a host that announces speeches, food, dancing and generally moves the event along. Though it doesn't lend itself to the colourful jokes that usually come from a friendlier MC, it does make everything incredibly efficient.
4. Scotch Is Not For Sipping — Everytime I met someone new (which was pretty much everyone), they would take me directly to the bar for a drink. Scotch would be ordered and I was not expected to slowly sip and enjoy this incredibly strong liquor, I was expected to shoot it back. Yup, I have not managed to stay sober for long at a Scottish wedding.
5. Bagpipes — Pipers play before and after the ceremony, and they pipe the newly married couple into the reception. It is tradition for the bride to offer the piper a drink once they have made it to their seats to thank him for his time and talent.
6. Tablet and Thistles — This could just be from my own experience, but both Scottish weddings I have been to had the Scottish thistle (an official symbol of Scotland) present and the served or gave away tablet as part of the party favours. Tablet is a sugary melt-in-your-mouth confection that tastes a little bit like a harder version of fudge (aka AMAZING).
7. Reels — Traditional Scottish reels are SO MUCH FUN. They are a mix between line dancing, square dancing, and highland dancing. If you are a non-Scottish female, be prepared to be flung around the dance floor by your Scottish dance partner. Don't worry about looking foolish, everyone will be too busy trying to master the steps to pay any attention to you!