I read somewhere that the key to success is to make more decisions. Makes sense to me - making decisions is hard. After all, you could be wrong.
Here's a handy rule of thumb I use in making decisions. Consider it a generalization of a question my boss once asked when I was proposing to spend some money: "What would you do if it was your money?"
I call it the Rule of Narcissism because "inflated self-importance" is exactly the point, plus it sounds cool. Replace money in the above question with X where X could be "company", "team", etc. and it's applicable in all sorts of situations.The Rule of Narcissism
Make decisions as though you were more important than you are.
Accurately applying this rule can be difficult, because frequently what's best from a higher perspective means a hassle for you. For example, I have an engineer who wants to cross-train with another team. That detracts from the amount of project work she can complete and requires the rest of the team to compensate for the weeks of the training rotation. From my vantage: hassle. From the vantage of my department head: more well-rounded talent, relationship building between teams, engaged employee. It's a no-brainer when you look at it that way.
Give it a try. Next time you have a decision to make pretend you're your boss (spouse, CEO, President, whatever) and see if you come up with a different choice.