I like to add extended techniques to studies. I really feel like they can challenge you to play it better in the end. In this study I alternated pizzicato with traditional sound. A good exercise for your tongue, articulation, support and flexibility.
Flute Colors arrangements
Sheet music with extended techniques for flute
Here you can buy and download sheet music of arrangements with extended techniques for flute.
Variations on well know flute exercises, traditional songs, but also modern pop songs. From Drouet and Bach to Justin Bieber and Bruno Mars. Have fun with extended techniques for flute!