Elements of a sharp photograph

[kabel]

Hello TE members, recently I had serious conversation with a world class photographer (Nat. Geographic) about what elements were needed to create a sharp photograph. Some of his ideas were first and foremost the exposure has to be perfect. Then the quality of the lens, and also the quality of a tripod which has to have very sturdy legs.
I would like to hear from TE members what they think are the most important qualities necessary to create a photo that is sharp.Thank you,
Sincerely,
Kabel