I play this variation in the third bar of the first part. Instead of playing F AF, BF AF, I play FD,AD,BD,AD,.
Coming back to the open D string all the time gives a sort of syncopated affect to the tune.

I play this variation in the third bar of the second part. Instead of playing DCDB, ADFA
I play DCDB triplet aba FA. Here I am using a straight forward technique of the triplet to vary the tune.