Know when you need to be tested. To maintain your IFR currency so that you can legally fly in instrument meteorological conditions (IMC), you must be tested every 6 months.
Perform 6 instrument approaches. You should have an authorized IFR flight instructor in the passenger seat when you do this. You should also do a combination of 6 precision or non-precision approaches.
Holding procedures. Slow down before entering the hold. Choose the proper entry. Compensate for the prevailing winds. Adjust the distance on the outbound leg to ensure a 1 minute inbound leg and required radio communications.
Intercept and track your course using onboard navigational equipment. This is automatically accomplished when flying an instrument approach.
If you fail to do this, then you have 6 more months to get current. Then you will be required to take an Instrument Proficiency Check (IPC). You may not file an IFR flight plan during that time.
