Like the other major symptoms of CFS/FM, brain fog is best addressed by using a combination of strategies and by developing new habits.

When people in the self-help program are asked to describe what they do to combat cognitive problems, they often give lists that are ten items or longer. Here is one person's description of how she handles cognitive problems. 
 

My brain fog is worst when I'm exhausted, so I try and stay within my energy envelope. The fog episodes have greatly diminished since I learned that.

Over the last several months, I've gotten organized. Orderliness helps to prevent panic and fog. And when I'm too tired and foggy to think, I put things off until the next day and get extra rest instead.

I use self-talk too, saying "this too shall pass" or "nothing catastrophic will happen if I don't do this right now." That keeps me from going into panic mode and meltdown.

I'm mentally sharpest in the morning before I get really tired, so I schedule all my brain-heavy activities in the morning and leave the simple tasks for afternoon. I also nibble some protein every couple of hours.

For more on treating cognitive problems, see the Fog pages of the Treating Symptoms section.