Well, we're still figuring that out.

Since this is so new it's kinda up to us to figure out how to deal with it. I encourage people to try anything they can & want to. If something works, please let us know, so others will benefit.

-Identifying triggers
Many people find that certain activities trigger them to start daydreaming.
Identifying and limiting exposure to triggers is one way to help.

-Common triggers:
music, tv, books, long walks ormonotonous activity

-Distraction
If you feel yourself starting to daydream, stop and change activities.
Get up and do anything else and come back to it when you're feeling more focused.

-Getting out in the public
A lot of times we just need to get out of our heads for awhile.
Go out and talk to people.

-Get up quickly and go to bed tired.
Many daydream in the morning.
To avoid this, make sure you get out of bed the instant you wake up.
To avoid daydreaming at night, go to bed when you're extremely tired.

-Allow limited daydreaming
Many of us really appreciate the comfortof our daydreams and don't want to give them up.
Instead, allow yourself certain times to daydream, and force yourself to get up and stop when your time is up
.
-Find other things you love, and focus on them.
Don't forget that we daydream because we love it.
It may take time and energy to focus, but if we can make the external world more fun, then we won't need to daydream as much.

-Meditation

Another common suggestion that people are saying works for them is meditation. Some have said it helps them focus, even if it doesn't completely eliminate their MD. 
Some have also said that Yoga and meditation help.