Introduction to double tonguing. Practice with and without your flute. Remember to play with a good sound even while articulating fast. Use a metronome for EVEN articulation. Try to equalize the tongue (T or K) and throat (K or G) strokes. Play the exercise with:
2/4 TTT-KKK-TKTKT-KTKTK
4/4 TTTTTTT-KKKKKKK-TKTKTKTKTKTKT-KTKTKTKTKTKTK.