I've converted almost all my bulbs to LEDs and other is a lot to know about them, some of which have been pointed out. Here's a dump of thoughts.
- All LEDs flicker but they should flicker so fast your eyes can't detect it.
- If you see a flicker, it could be from bad wiring, a bad fixture, a bad switch, or "dirty" electricity. If they flicker everywhere in your house it's likely "dirty" electricity and you'll need a whole house filter to clean it. This happens when you run your house on a generator sometimes because generators are notorious for producing dirty electricity.
- LEDs almost never fail, the other electrical components in the bulbs (circuits) usually fail. This is typically the difference between high-quality LED bulbs and lower-cost bulbs.
- Understand what "color" of white you like. Lots of LEDs are like 5000K which makes your house look like a Walmart (IMO). 2700K gives that old fashion warm incandescent look. Some bulbs offer a switch to adjust the color, if you don't know what you like start with this.
- Some older fixtures may not work with LED bulbs, so if they don't work at all it could be because of that. This is common for those old workshop, tube fluorescent fixtures.
- Some LEDs can not be dimmed so dimmer switches won't work. Check the LED packaging to see of the LED is dimmable.
- There is an inconsistency between the conversion from wattage to lumens between manufacturers so if one company says their 8-watt LED is like a 60-watt incandescent, producing 700 lumens, that doesn't mean that an 8-watt LED from a different company will produce 700 lumens. Check the package.
This is just some of my experience....