At the risk of sounding cheeky, I feel the most musical answer is to play what sounds good. So, given an exercise like this, I would listen to it as I played it, and then adapt it according to what sounded pleasing or logical. Music is, after all, a form of communication, so make it say something you want to saysomeone I follow suggested playing scales in 3rds to make them more musical and I really think it does. I am having trouble playing them descending tho, or maybe I am just confused?