Well, you seem to have gone through the usual tricks. Recycled cartridges do not retain as much ink or hold ink for as long as new cartridges. If you do have luck with recycled cartridges, they will only last for so long, which unfortunately isn't that long at all.
The best way is to, of course, use new cartridges. Or, as a somewhat round-about way, invest in a laser printer (toner tends to last longer and not cost the horrendous amount ink cartridges do, and if you do heavy printing not only do you get good image quality but a long-term investment that pays off compared to inkjet). Sadly there is not much more you can do in extending the life of used ink cartridges.
The best way is to, of course, use new cartridges. Or, as a somewhat round-about way, invest in a laser printer (toner tends to last longer and not cost the horrendous amount ink cartridges do, and if you do heavy printing not only do you get good image quality but a long-term investment that pays off compared to inkjet). Sadly there is not much more you can do in extending the life of used ink cartridges.