Swift may only have been around for six months or so but there's more than enough tips and tricks to make this year end roundup article a great read. I'm sure even those developers that jumped in early with Swift will find something here that they didn't know. There's also an old trick I've been using for a while of an alias to delete Xcode derived data but I do like Clay Smith's choice for the command name.
What a fantastic gentle introduction to SceneKit from Silviu Pop. He goes over some of the core concepts of SceneKit and then presents challenges with solutions to guide you through the learning. There's also Part 2 and Part 3 which cover more advance topics but are again so well written that each challenge just seems like the next logical step.
Writing these telescoping constructors in Objective-C was never something I gave much thought to. It was a good practice I learned early to ensure all your constructors end up going through one method. Tony Arnold points out how much less boiler plate code we have to write to accomplish the same thing in Swift.
Karl Voskuil has open sourced some helpful classes and utilities for working with SpriteKit. There's a class category for using gesture recognizers in a Scene which means you can encapsulate the touch processing into a Node subclass and keep the scene from getting bloated. Worth a look at the background loading of assets in a Scene as well.