My "Theory of Everything" as it relates to work & productivity:
Step 1: Build a useful project, even if it is inefficient at first.
Step 2: Use Pareto Analysis, Actionable/Measurable Short Term Goals, Rapid OODA/Iteration Loop to delegate and automate project from Step 1.
Step 3: Keep trying to reduce system from step 1 to require minimal input from yourself - ideally, 1 hour or less per week.
Step 4: Maintain previous system(s) while looping Steps 1-3 (probably 1-2 successful iterations per year) until you have a bunch of ultra-effective projects, designed to pursue your aims, delegated and organized into less than 20 hours per week of total work time for you.