Stay off of social network sites to whatever extent you can, and if you do use them, use them for nothing more controversial than vacation photos and your kid's birthday party pictures.

Stay with discreet professional providers rather than screw around with old flames or gals at the office.

Never give your SO any reason to be suspicious in the first place so she doesn't hire a PI to check you out.  Once she does that, you're screwed anyways.

Or, marry or date someone who's cool with you seeing providers in the first place if you can manage to find such a person.

you can scub everything (theoretically) but a cheater can still be followed.  I submitt that an affair with it's emotional demands is more likely to be found out than a random hobbying events...  with no contact in between & no visits to the same person.   A cop friend followed by ex.  (I didn't hobby until 30 years later.)  

At a minimum, keep your antivirus, anti spyware up to date.  check your installed programs for anything unknown.  Scrub your computer often with an overwrite program like CC Cleaner.  Use a hobby phone.  Don't have your favorite hotels in GPS.  (As a coffee freak, I do have a number of coffee shops in my GPS.  It's no big deal if you can see a hotel from there.)  
Do not use your CC anyplace you shouldn't be.  I gas up the day before...   pay cash for incidentals you might buy (like that coffee).  EX-Pass toll payment can track you...

I don't know why this is news to anyone.

taking precautions to minimize tracks is basic...  knowing that nothing is or ever can be 100%.  Yes a PI could follow you or attach an illegal GPS tracker to your car.  (It's not for a criminal case unless your SO is waiting when you come out & commits an act of violence upon you!)  

It's kind of funny...  the story shows a "NoTell, Motel" which is unlikely place for a hobby meet.

What a waste of fucking time this story is.  

They say technology will catch you.
They give 3 big examples of it happening.
They tell us we are pre-dispositioned to cheat.
They let a comedian say stupid shit for 45 seconds.

Then, nearly 5 minutes into the 'story', the best example they give of catching a cheater????  Looking at paper phone records for long conversations.  A technique available since long distance phone calls were available.

The PI's tracking digital footprints part of the story?  Some guy doing internet searches for your email address.  Because you know, getting another email address is a difficult, time consuming, expensive process.

Horrible.