Creating example apps is still a good way to learn Swift and Xcode. I have included the steps to create a code-only initial iOS software project using Swift 4 within Xcode 9. This is my starting point for our app project development.
There are numerous Xcode 9 tips and short-cuts that one learns during their journey along the app development path. Here is my growing list.
Using CocoaPods integrates third-party software libraries into my app's Xcode project cleanly. Pods have several benefits including professionally developed tested code, great usage documentation, and version management independent from my project code.
It only makes sense to develop apps that operate natively in the world's languages and their diverse cultures. To do it right, it takes a healthy attention to detail.
Having worked on some complicated systems with embedded software, I appreciate the list from this amazingly well-written paper on best practices in software development independent of software language.