The best practice is not to print with outdated inks. The best practice is to drain and refill empty cartridges.
Sometimes with very old inks that have not been printed in a long time (like 4 years), the printer is mainly printing very thin viscosity of ink. If you were to shake the inks and run 3-4 power cleans to bring freshly shaken ink to the print head, your experience may change. Possibly, the pigment that has fallen in long ink lines can suddenly foul the dampers when the printer is put back into use.
The best practice of all with printers that have been sitting for a few years is to PiezoFlush them out.