the whole waking day stretches long before you, even with appointments, chores, and other regular duties. No matter what, you should be able to get something concrete done within a few hours you reserve just for this purpose. Each day. No excuses.
And, if you are really organized, you get several things done, including those of commitments, necessity, and free and spontaneous personal choice. Pity the dullards who bemoan their retirements saying “There’s nothing to do” or “I don’t know what to do”, or “I can’t get started.”