Voila! Here are the D-Pad touch sensors. I have outlined the area you want to cover in red.

Using tape (I recommend black electrical tape, but others have said it works with clear scotch or packing tape, just be aware it may pull up after a while and cause buttons to stick!), cover the highlighted areas. This really cuts down on accidental button presses.

After some testing, I applied the tape to the top and bottom touch connectors. This resulted in the smoothest operation with fewest accidental button presses. Always be sure to test (and make sure you like how it feels!) before you complete reassembly.