If you want to strengthen the glutes, sidelying clams and prone hip extension are a great place to get started. But lying down exercises do no carry over to functional activities. So next level up is banded walks. Most people place the bands round the knees and get working on those glutes. Again, not a bad place to get started, but the most optimal placement for the bands is not around the knees.
What does Research tell us?
Based on “Progressive hip rehabilitation: the effects of resistance band placement on gluteal activation during two common exercises.” article by Cambridge et al (2012)
This study looked at three resistance band placements (around the knees, ankles and feet) during banded walks, which were utilized to provide a progressive resistance to the gluteal muscles.
The band placements offered a progressive increase in resistance for hip rehabilitation, specifically the gluteal muscles. The added benefit of placing the band around the forefoot was selective enhancement of the gluteal muscles versus TFL presumably by adding an external rotation effort to the hips.
So what does that mean?
Start with bands around the knees, then move it to the ankle, but the real activation of both Glute Medius and Glute Max is when the band is placed around the forefoot.
Cambridge, et al. Clin Biomech (Bristol, Avon). 2012 Aug;27(7):719-24. doi: 10.1016/j.clinbiomech.2012.03.002. Epub 2012 Mar 30.