A very common cause of misery is the desire to control & take perfect decision in life. I believe that there is NO decision that is perfect till it is being executed perfectly. A very good decision may be proved a failure if not executed well, while a not-so-good decision may be translated into success, if executed well.
Another common botheration is fear of failure, while making a choice/decision. No one else should make a choice for me, I have to face it myself. Everbody's life is full of successful events & failures, no one can be successful always & in all his/her life-events.
One fine day Gandhi Ji made a decision to choose a life of sacrifice, peace and non-violence. People around him, considered it a very stupid choice to leave the comfortable life full of wealth, facilities & securities. But he found meaning of his life in the decision, not only he himself but many inspired souls get elevated & dedicated themselves for the cause of country. There may still be a debate and perspectives, some may consider it, as imperfect decision and some may consider it otherwise.
There are few simple steps to practice for making an effective decision for a situation in professional life or Project Management:
1- Understand the situation & it's essence, severity & impact
2- Collecting enough data, analyz it. Try mapping data & situation to ensure you understood the essence in entirity.
3- Evaluate different available decision options;
4- Preparing pros & cons
5- Building mind-map;
6- Considere past experience of any such similar situation & applying learning
7- Knowing all listed above, you would finally arrive to a conclusion/decision with estimated risks.
8- Now prepare execution-approach to cater to the situation, I am sure now it has better chances of success.