We all know that undereye area is very sensitive due to the thin skin that allows for any darkness or redness to show through. It is therefore extremely important to conceal the dark circles even if it is the one thing you do about your makeup in the morning.
It is equally necessary to apply your concealer on moisturised skin, to prevent the concealer from sinking into your wrinkles. Your concealer should be at least 1 shade lighter than your foundation.
My favourite concealer is Estee Lauder Stay-in-place concealer, with SPF 10. The coverage is medium to full and it is indeed long-lasting.