I first started using foam hip pads, the ones with removal pads that go into panties. They were ok, but I was never able to find a good size that fit me right, it was either a little too big or a little too small.
Too big and I would constantly get hip droop, too small and it was very uncomfortable. Plus, it looked like big warts on my hips and did not give me the look I wanted.
I finally ponied up for silicone hip and butt pads, and I’ve never looked back. Yes, they are heavy, and yes the first couple of times it is awkward to put and to get it close to symmetrical, but after you get a system down pact, it is as easy as breathing. You also get a much natural looking and feeling hips. It is expensive, but well worth it for me.