- Google for software alternatives and try every one of them
- Take advice from others
The first means that you are going to learn from your own experience. In my own experience, this is a slow and painful way to learn.
A much easier way is to learn from the experiences of others. At that is where AlternativeTo comes in.
AlternativeTo is a website which lists alternatives to web-based software, desktop computer software, and mobile apps, and sorts the alternatives by various criteria, including the number of registered users who have clicked the "Like" button for each of them on AlternativeTo.
Unlike a number of other software directory websites, the software is not arranged into categories, but each individual piece of software has its own list of alternatives, permitting a more tailored listing approach.
Searching through AlternativeTo was how I found a number of software tools that I currently used when I decided to stop software piracy.