Here's a trick that I've found useful: If you have a phone that can do slow motion capture (I have a Pixel 2, but this also works with an iPhone), go to a Home Depot or Lowe's and take a slo-mo (240fps) video of the LED bulbs they have on display. Most flicker horribly on playback, including the expensive Cree bulbs.

The built-in LED spotlights that came with my house flicker like a rave concert whenever I capture a video in slo-mo. It's unsettling.

Phillips LEDs, especially the Scene Switch bulbs, are flicker-free according to my tests. Surprisingly, older CFL bulbs flicker much less than LEDs.