Start running and cut out carbs. Carbs is a huge factor.
It's hard when we can't move around as much as we're used to! Simple tips: stay active, whether that's actually cardio, or just not staying seated for hours at a time. Agree that cutting down on carbs/sugar/booze can make a huge difference, too. And try and get enough sleep!
Get a standing desk and take walks whenever possible.
Unfortunately, I think the only remedies are eating less and working out :((
30-day butt workout. For added intensity, I wear a heavy slipper or shoe on the leg I am exercising. https://www.blogilates.com/30-day-butt-lift-challenge/