I don't have the patience to explain in detail, but here's my basics:
Established and STABLE tank with excellent water parameters
Proper lighting
Patience
non-aggressive clownfish (some clowns just beat them to death)
good husbandry habits for maintaining your tank
proper flow
a good understanding of any feeding requirements. I've noticed that some species like to be manually fed, while others prefer to just catch left over fish food that floats by while you're feeding your fish.
Proper substrate for their foot. Some anemones like rocks, some like sand...
Starting with a healthy anemone will make the odds better that it will survive
NOT attempting to move it to where you want it, but allowing it to find it's own happy place