In 2009, I put together a little tutorial for creating slots for collar stays on an under collar. I had posted the tutorial on a blog which is now defunct. I got such wonderful feedback on the tutorial that I decided to repost it to my new blog. Please update your bookmarks!
Collar stays are a great way of making sure your collar points stay firm and do not bend out of shape.
The method I use allows you to remove the stays easily before laundering and ironing.