There’s an adage with developers: write code that the complier can build and humans can understand. Compilers are relatively forgiving when it comes to poorly-named objects, excessive use of copy-and-paste, incorrect comments, and unnecessary complication in code. Humans, on the other hand, tend to get confused a lot more easily, and so you should focus your code on satisfying the latter constraint.
Cory House has a Pluralsight course full of tidbits that help you write cleaner code. I watched this not too long after reading The Art of Readable Code, and these two resources fit together quite well. Much of the advice is simple, but House walks through the topic in an understandable manner and ties together a few basic themes. Watching this series has helped me think more concretely about how I can improve the code that I write, which helps out me as well as my co-workers and successors.
Even though House’s course focuses on object-oriented development, I think there are a number of things that a T-SQL developer can take from the course, particularly when it comes to branching logic, appropriate use of comments, and attribute and variable naming.