The first step in systematizing a process is to write it down.
Often, the documentation you create in this process is all the system you require. The next time the task comes up, you can pull out the file and save the relearning. It also becomes the core of the training manual for new employees, which is often one of the most valuable systems you can build.
If you are struggling to get all the steps down, try the “backwards” approach. Start with the end result and then determine what you did right before that, and so on, for each step.
Start today with documenting the opportunities to build systems that can be leveraged throughout your business.