aptitude

favor, one-sidedness, partisanship, prejudice

endowment, faculty, flair, genius, gift, knack, talent

addiction, appetite, fancy, fondness, like, liking, preference, taste

forte, speciality, specialty

convention, custom, habit, pattern, practice (also practise), routine, trick, way, wont

eccentricity, idiosyncrasy, kink, oddity, peculiarity, quirk, singularity

affinity, bias, disposition, impulse, inclination, leaning, partiality, penchant, predilection, predisposition, proclivity, propensity, tendency, turn

ear, eye, mind, nose

feel, hang, instinct, touch, way

capability, competence, facility, proficiency, skill

capacity, potential, power

forte, specialty