Take a rubber sensor gasket off an older gen Moto Droid Model. You can modify if you see fit. This is the best thing I have personally found that works as buying a replacement Moto X can be pricey as you will have much difficulty trying to find JUST the rubber gasket piece. Even if you purchase a moto droid Razr from a few years ago for $20 and jsut harvest the rubber gasket out it will work and save you $$$.
I have found out what the major issue is if you are using a "silver" frame digitizer. These are the most common on the market that we have been finding. The problem is similar to the mini, but different is the sense that the tape you use needs to be placed in between the cables and the glass behind where the cables attach. The mini you place the tape over top of the cables so as it does not come in contact with the frame. With the AIR the same thing is needed, but additionally placed between where the cable feeds into the digitizer and where the glass on the outer edges meet it. You have to be VERY careful as to not "over bend" the digitizer cables and you must tape it AS CLOSE to the base as possible. Hope this helps... took us about 3 hours of playing around to realize.
After attempting the ESD tape switch numerous times, I noticed I was STILL having some issues with the digitizers every once in a while. I discovered that the ENTIRE digitizer assembly will short itself out if the edge comes in contact with the metal frame. I added some extra 3M tape around the entire frame to add a "buffer" zone to give just enough space to make sure no parts of the digitizer are touching the frame. Also you want to make sure the LCD is screwed down in all four corners without any part of it pushing up on the digitizer. This worked for me finally after a grueling 6 hours of attempting every fix in the book and studying the cause and effect of the digitizer coming in contact with the frame is certain spots.