"[E]mployers need not settle for patterns of absences or even suspicious excuses for absences. Keep in mind a few best practices to combat FMLA abuse: Recognize whether the employee is seeking leave that might be covered by the FMLA ... Require that Employees complete a written leave request form for all absences ... Enforce usual and customary call-in procedures ... Prepare a list of probative questions you ask of all employees when they call in to report an absence ... Use medical certification and recertification to your advantage ... Conduct a comprehensive audit of your FMLA policy, procedures and use of leave[.]"