As always let me keep it concise - and talk to you about a (very) old time management and prioritisation lesson that was passed on to me in my early days. It revolves around the story of Stone and Sand - to help you focus your life and work by visualising how you prioritise
Let's equate the time we have available in a day, week, life - to the space available in a jar (since we don't have infinite time!)
If we take our time (jar), and we fill our time on lower value things or activities first (sand) - the jar will be full with no room to fit in the stones (key priorities, activities - what really matters)
However, if we focus and plan our time around the key activities first (stones) - we can fit in the other activity (sand) around it easily
Plus - if you plan your stones first - you won't get that feeling at the end of a day where you did a lot but not what you really needed to!