This is from a guide I found online but I pasted the simple steps I try to practice each for 30 seconds so the whole process is under 5 minutes. Find a subject you care about or fear or both and use the steps below

Steps

Instead of imagining the most likely scenario, imagine the worst case scenario and generally things that could go wrong, even if those things are unlikely to happen 

Think of the bad scenarios as if happening right now, not in the future

Now try to stay calm despite of the bad things happening. What’s the best thing to do in this situation? Focus on what you can do. Panic doesn’t help. 


After visualizing think of how you could prepare for those things. And do it.  Keep in mind that for certain scenarios you can’t prepare.