I combat this by NOT tying unweighted flies on with a loop knot. This only works with turned up eye shanks. What I do, and was taught this by a friend, is to double over the tippet about three inches depending on the size of the fly. Run the loop over and under the fly so that the leader goes straight through the eye, under the head of the fly, back up over the head and straight out the front of the eye. Then tie a uni knot, as in double over the tag and then four times around itself. When the knot tightens, the knot should be resting between the head and the eye of the shank. If that makes sense to you. This allows the leader to run straight out the front which helps to keep it oriented in the water. Of course this is not 100% way to keep your flies from flipping and flopping. All of my unweighted flies are tied in the round, so there is no top and bottom ex. marabou tubes, intruders etc.