The laces on dress shoes have always driven me crazy, ever since I started wearing them. Unlike sneaker laces, they have a waxy coating on them that makes them slippery. As a result, you have two options:
a) Single-knot and constantly bend down to re-tie them
b) Double-knot, which doesn't look great and is a pain to undo
In this video, Terry Moore shows that with one small change in how you loop the knot (under instead of over), you end up with a much more secure single-knot. I started doing this and it is well worth the effort. However, I made small a tiny change to his technique that makes it even easier. Instead of reversing the looping part, reverse the initial X you make when tying your shoes instead. This is a lot easier than going against many years of muscle memory for the looping part.
Either way, problem solved - EZPZ!