There have already been a number of good accounts of success, but I will add my experience.
I have a female meleagris which has been thriving in my tank for 14 months. This has been my only attempt at leopard wrasses. I believe the key to my success has been careful planning and patience. I knew I wanted to keep this fish well before the tank was established and I wanted to ensure success.
My tank is a 180 with refugium. There is a 2'' sand bed in the display and 6'' DSB in the fuge. I seeded the display with Kaelini live rock and my fuge with the same plus an assortment of organisms from Inland Aquatics. I did not experience a major nutrient spike due to the high quality of the rock I used. Next, I allowed the tank to mature for six months before adding any fish or coral. During this time, I used the algael succession as a gauge of system maturity. By the time coraline aglae predominated the system was crawling with a great quantity and diversity of tiny animals. My meleagris was introduced into this environment as the tank's first piscine inhabitant.
I acquired the meleagris at about 2.5'' from a not-so-great LFS. She was in a rather bare holding tank and was not eating. I did not QT. I performed a 1.5 hour drip acclimation. Initially, the fish disappeared into the sand and was not seen for 4 days. After she emerged I soon saw her actively feeding on the live rock. I began offering frozen mysis and cyclopeeze every third day, which she took to on the second attempt. It has been smooth sailing ever since. Now at 14 months, she has grown over an inch and has become rather fat. She displayed aggression toward a mystery wrasse I introduced subsequently, but they eventually learned to live together, albeit usually on opposite sides of the tank. Unfortunately, I lost the mystery wrasse do to jumping, but I have since installed some fine bird netting over the tank.
The meleagris now eagerly takes small pellet food, which is given 3 times daily.
My method my be a bit extreme, but like I said, I wanted to do everything I could to ensure success. The important components are probably a mature system, a refugium, a sandbed, timely introduction of appropriate foods, absence of aggression from other fish, a healthy specimen, and a patient aquarist. Hope this helps.
Kris