Set a short deadline

You never want to create a course and spend more than a month, even if you are asked to create a course where you don't know anything about that technology just yet.

You must set a tight deadline where you commit to create a first draft of the course.  Usually have this be no more than a month from when you start working on the course.  If you're already familiar with that technology, the deadline for the course should be no more than 2 weeks generally.

Remember that the goal is not to create the perfect course in that time.  The goal is to come up with a minimum viable course that you can start using in your first class as a textbook.  You need to test the course to real students and find out what's missing in that course, what's working really well in the course, and see how you can teach certain concepts a lot better.

These valuable learnings cannot be had, unless you interact with the students, see their progression, see what type of questions they ask, what emotional concerns they have, which assignments are super difficult, which assignments are too easy, which concepts are really difficult for students to understand, which section in the course, you have just done a really bad job teaching, which you have done a good job, etc.

Create a course you'll use as the textbook for the real class that you will be organizing.  Invite 3-5 people to take the course at the end of your self imposed deadline.  This will really force you to be creative and find ways to make the course effective.