In this example, we take a pretty common kind of pentatonic tapping sequence that you can find in solos of everyone from Nuno to Howe.
I use this type of moving pentatonic shapes in my own soloing quite a lot. Here however, we incorporate open strings in, substituting "regular" notes in the sequences for open string. Now, this is not a completely uniform sequence. It does turn around on itself on certain parts, so watch out for the slight discrepancies within the patterns, and you will be OK.
You should of course try incorporating open string (as an exercise at least) into other keys than Emin.
Emin is a good place to start however, because all open string are included in the Emin pentatonic, so you really can't go wrong!
Amin Pentatonic would also be a good one to try, even though the B-string is not included in the pentatonic. It will be 2nd or 9th degree however, so it will work very well nonetheless!