Step One: Gather information.
What, specifically, am I deciding on? Clearly naming it is half the battle.
What is the context? Does this pretty much just affect me, or is this going to affect others? How much? What is their preferred outcome? Why do they prefer that outcome? Ultimately, does it matter what other people prefer? As a 20something without a child or relationship, I am able to make some totally selfish decisions. This may not always be the case, so I have been taking risks now. There are pros and cons to every situation you're in--maximize the pros you have working for you.
Step Two: Decide what my specific priorities are.
If I know, that's great. If I don't:
I created a three page list of ethical standards and quotes by which I want to live my life, sometimes it's helpful to go to my abstractions when I'm confused about how I want to deal with a specific instance. I only refer back to it maybe twice a year. Perhaps I should do it more--it's always helpful when I'm feeling disoriented about my priorities.
Step Three: Remind myself that, often, the best long-term decision is the slightly less appealing short term decision
This can be as simple as deciding to read a book instead of sitting dazed in front of a screen consuming a movie--I want to be knowledgeable, and books are high-octane vocabulary & well-contextualized knowledge builders.
Other times, it's far more complex and difficult, e.g. withstanding a bit of heat to maintain a prior commitment or standard.
Step Four: Execute decision, and remind myself that life is a work in progress to avoid decision remorse
So long as I'm making a decision I am not ashamed of, I remind myself that life is a series of small choices, and I can fine-tune along the way. We can only do the best we can with the resources available at the time.
Hindsight is a beautiful resource, but that's not a resource available to you in the moment that you're executing an action, so do your best and then give yourself a break.
Generally, it's better to take action repeatedly, fixing things along the way, than it is to not take any action at all.
Don't fall for the myth of a beautiful single execution. Life is a series of small actions, and the great thing about it is that you can pause between them and reflect on how these actions are working for you.
Personal example: All of these moments let me stop, pause, gather information (including my feelings) and decide how to proceed. At any moment I gave myself permission to chart a different course, which is what I will continue to do on this path. I don't presume to know what life will be like in x amount of years because I'm continually refining my trajectory, goals and priorities. Don't fall for the myth of a grand execution.
Myth: I just uprooted myself from Canada and committed to 7 years in the USA to finish my PhD
Reality: 18 months ago I began researching schools and talking to people who had done grad school, because I was considering that instead of the work force, THEN
I talked to profs who knew me, asking questions and getting feedback specific to me, THEN
I was invested enough in the idea to ask for letters of rec, THEN
I made a short list of where I could see myself flourishing, THEN
I filled out my applications, THEN
I applied and got acceptances/rejections, etc. etc.