Pentatonic scales

How can I learn to better improvise?

Finding anchor notes, and the pentatonic scale

Something useful about the pentatonic scale is that it gets rid of the tritone.

The tritone has this tense sound, and it's just not folkloric enough so we'll take it out of everything. 

I noticed that the tritone in any one of the modes contains the two notes that distinguish it from its neighbours. For example, the tritone in Ionian (Major) is F–B (or B–F), or the fourth (which is Perfect) and seventh (which is Major) notes. If you make the seventh minor, the scale becomes Myxolidian. If you make the fourth augmented, the scale becomes Lydian.  

On a flute, the D and G stand out in terms of fingering (closed left hand, and open/closed right hand). The C/Csharp is an odd note, and not worth dwelling on. What are the pentatonic scales that we can create by using D and G, and avoiding C? It turns out, there is no pentatonic scale with these characteristics, that uses F. That's because, if we use D and G and not C, then E must be used, lest we create an interval of a third on both sides of D. If we use D, E, and G, then we can't use F. This means there is only one set of notes we can use to build a pentatonic scale with the flute, that uses D and G but avoids C, and these are D– E–G–A–B. There are five ways to arrange these notes (TODO: list Major, blues major etc).

So, given that we can play each scale with two keys on a flute, which one should we pick? Let's use what we've learned about the quality of the modes.