To complete missions energy is very important don't waste 5 above percent.
I'll tell you some smart Strategy and calculation's to complete more mission's.
Running out of energy while playing game will get you bored soon.it happen's especially when you don't care 13% 14% energy and refill with booster.boosters are very useful to get instant refill but smart players doesn't waste their energy.to be smart player of rising star you need a smart Strategy to use energy 100%.
If you are doing the same as I told above so stop doing right now and have a look at this...
1% energy take's 5 minutes to fill and if you are wasting 12 13 14 % energy and refill instantly by using energy booster (cold pizza slice,discarded pizza,) when your energy level at 12 13 14 % so you are wasting 60 65 70 minutes of refill time, to avoid this loss you should make your own Strategy or follow someone's to choose missions
Here is my Strategy.
When my energy level drop near 12 14 % I wait for 15 or 5 (15 min when at 12% and 5 when at 14%)when my energy level get 15% I start the mission like Radio Interview or Illegal Busking.these mission complete in 5 minutes and my energy fill only 1% which is negligible than I use energy booster to refill and start mission which consume 100% or 80%.
If I choose 180 minutes mission which use 100% energy than my energy level will be 36% at the end of missions.in this case I start mission which use 20% energy and complete in 10 minutes.at the end of this mission my energy level reach 18% and I wait for 10 minute's and again my energy level reach 20% I start 10 minutes mission.at the end of the my energy level reach at 2%.
If I choose 300 minutes mission which consume's 100% than my energy level will be 60% at the end of missions.in this case I start music lesson mission which use 40% energy and complete in 60 minutes.at the end of this mission my energy level reach 32 and I wait for 15 minute's and again my energy level reach 35% I start 25 minutes mission.at the end of mission energy level reach at 5%. music lesson mission are useful to keep ego balanced which increased by completing other missions.
don't keep doing same mission again and again it will decrease your starbit reward and also increase ego per mission
keep shuffling missions and try different combination to use 100% energy
definitely this Strategy will help you to take full advantage of usage maximum energy and also will increase your starbit reward and skills.