Plus one for hand work. I own the Leigh, (which I think is fine for production i.e. Kitchen drawers etc), along with a host of other guides to help cut dovetails , but since I don't do that sort of work I haven't touched it in years.
I finally decided enough was enough and tried to learn to cut them free hand. They're still not great but I'm feeling pretty good about them.
Two things I learned. First find a system and absolutely stick with it and practice. Although you will have to experiment with different techniques, once you find what works for you continue to practice and build muscle memory. There are a ton of websites and I would suggest Derek Cohens. Also, while not necessary, a Moxon vice is really helpful. Plus it's fun to make.