I thought of a few five-second skills like this:

• remembering that a purpose of engaging in argument is to update your map
• realizing you should actually spend time on activities that have proven to be helpful in the past (related to this)
• noticing when you have a problem and actually applying your creativity to solve it (similar to this)
• recognizing a trivial inconvenience for what it is

I noticed that all of my 5-second skills (and Eliezer's also) involve doing more mental work than you're instinctively inclined to do at a key point. This makes sense if the main reason people are irrational is due to taking cognitive shortcuts (see this great article; feel free to skip down to "Time for a pop quiz"). So maybe we could save some labor identifying or at least acquiring 5-second skills if we learn to be comfortable with constant reflectivity and hard mental work.