I have been working full time employed since my university in different IT roles for almost 5 years. After I had to do a lot with freelancer developers, I realized that IT freelancers, no matter if developer, project managers or consultants, are not only earning at least, minimum 150 % more per hour than myself (including sick days, vacations and so on, I did the math...) but have also more freedom and flexibility and far more variation in their work life.

Thus, I consider myself becoming an IT freelancer. However, of course I understand, that it comes with a risk of not getting enough or any work from other companies and thus not getting any money at all. What is a more safe way for a transition from a full time employment to freelancing? Is it usual for example to switch the current full time employment to a part time employment to be available, lets say, every Wednesday for your customers in your freelance role? Or is that unrealistic since the limited availability will not be enough for most, if not every, potential customer? Or, is the only viable alternative to leave the current full time job and start freelancing full time?