When I was teaching we would dedicate a whole day, as many schools do, to it.
Staff and pupils dressed in tartan and we would have a St. Andrew's day concert. where each class had to contribute a song, poem or dance. Parents were invited and they loved it!
We always had quite a few pupils who were Highland dancers and and those learning the violin would also play, . PE that week, would be devoted to Scottish Country dancing.
There was also a Scottish feast in each class, where pupils would get the chance to taste various Scottish treats.
I loved St Andrew's day, it was hard work organising, but so much fun.
In happier times, many of us would go to a ceilidh.