This are questions for a fitness trainers... I would not expect many of them read a forum like this.
You can find many videos on youtube for muscles of gluteal group, but a lot of the exercises would also include working on thigh muscles, which would look extremly bulky and masculine (without HRT), and you would want to avoid that. Waist can only be really trained with one muscle (for which I cant remember the name), and you train it by exhaling the air out, and "push" that muscle towards back. You can wear training corsets, some people report some effects (many trans girls like to exaggerate a bit...) and really low body fat percentage is your friend. But only for waist.