When learning new skills 1) Understand that you need to fix something. 2) Work out what you are to do and go through it in practice. 3) Do it enough so that it is "automatic" in your brain and you don't need to think out each step.
Studies have shown that one hour of practice a day followed by the sleeping--- when your brain is making these new connections, is more efficient than just a whole lot of hours on the water.
Most of us can't sail every day, but it helps to know that even little short sessions help get to the "automatic"..