If there is no plan, then there is no purpose to your training. Though you may be having fun, will it be as much fun when you stop seeing improvement?
Why are you doing that workout today/tomorrow/etc? "Because I want to get better" is not a good answer. What aspects of your fitness and weaknesses are you addressing?
If you can't answer these questions from a planning and purpose perspective, then you're just having fun with hard exercise. Though some make call that training, it certainly can't be called preparing.
Prepare to accomplish your goals by training with purpose.