David Rock in his book “Your Brain At Work” makes a mention of the fact that parts of the brain involved in thought related processing e.g problem solving , creativity make most use of energy e.g. glucose , oxygen.
As a result of this “Prefrontal Cortex” involved with this function needs to be used optimally once when most needed.
For this to happen meticulous white board planning needs to happen to determine the prioritized list of tasks to engage this part of the brain with.
Generally this planning should happen at times when we are least loaded e.g. early morning , late evening vefore bed.