Pattern picking was mentioned earlier [ I DO NOT SEE HOW IT HELPS AKE], the alternating bass is only a start and tends to restrict to 4/4 tempo, the next step is to think about putting basses off the beat a little like bill broonzy and using single string bass to provide variety from the predictab ilty of alternate bass, howewver this styleis not the easiest .
thumb melody with thumb pick or flatpicking with plectrum is easier for scots pipe tunes, i suggest looking up carter picking tutorial