The first and the foremost thing is the understanding about the ideal base condition of the equipment, its operating parameters, thorough understanding about machine name plate capacity, capability etc.
Regular focus and actual operational & maintenance work to ensure that base condition is very important for maintaining anything.
Making the Planned maintenance schedule as per the OEM suggestions and company's collective experience is very important, Following that PM schedule by religiously implementing that schedule is the next step. (Preventive, predictive OR Breakdown maintenance)
The operators should own their machines and must be responsible for at least the CLITA (cleaning, lubrication, Inspection, Tightening and adjustment) aspect of their equipments.
TPM, OEE, Six sigma, Various RCA techniques, MTTR, MTBF reports etc. can help you achieve these objectives.
More than anything else, the most important factor is the willingness and effort to make a difference, eliminate the intermittent minor issues, train operatives & inculcate the feeling of ownership, kill any of the material issues and niggling problems...