Very tough. Concealers?
Liver issues. Dark circles is due to issues with liver - try nac 1200mg twice daily for 3 weeks. After that taper slowly and stop. Locally apply vitamin k cream twice daily.
Easiest? None. Simplest way is with topical meds/creams/moisturizers and common sense. Due to being caused by multiple causes, eliminate smoking, correct iron/ thyroid deficiencies, sleep better but not in excess or too little, and i you have allergies like i do, we are both screwed. More permanent help regardless of causative agents include laser peels and restylane(expensive but easy). I'm considering butt fat.