For all 2-cartridge ink-series printer models, if your printer is printing blank pages or poor image quality (i.e. missing text/light colors, etc.), then refer to the appropriate recovery steps below. 

Printing Blank Pages or Faded Text?

1. Make sure that the ventilation seal has been removed. On some cartridge models, the seal can be very easy to miss. Carefully inspect the cartridge for a plastic strip that will usually be a color tab and say "PULL" or "REMOVE".
2.Use your print utility software or printer panel controls to run a print head cleaning. This feature can usually be found in the maintenance section of your printer's features. If desired results are not achieved the first time, repeat 1-3 times as necessary.
3. If you have a print head type cartridge (a cartridge that houses the ink and print head in one unit) you can also try the soaking technique available: Clogged Ink Cartridge Recovery (video) 

4.a. To improve print quality for an integrated ink cartridge, you may need to clean the nozzle plate and/or rear electrical contacts. Using an isopropyl alcohol dampened lint-free moist cloth, gently blot the nozzle plate until some ink is drawn out and absorbed into the cloth. Ensure rear electrical (gold) contacts are thoroughly clean of all ink residue and lint fibers. Ensure cartridge is dry before re-installing into printer.
Cartridge Plate n Contacts3 with inset
4.b. Using a cotton swab dipped in isopropyl alcohol thoroughly clean the flexible cable contacts inside the printer. Ensure contacts are thoroughly clean of all ink residue and no lint fibers remain on cable surfaces. Ensure flex cable contacts are fully dry before re-installing cartridges back into printer.

NOTE: Only use isopropyl alcohol or de-ionized water on cleaning cloth or wipe. If nozzles are allowed to dry or clog, white streaks may be visible in the printed text or graphic (similar to image shown below). Printing alone may not remove clogs from the nozzles, sometimes a ‘cartridge clean’ may need to be initiated from printer’s control menu or printer software.
Most printers include some form of a test page under the tools or maintenance menu. You may also select an Inkjet411 test print by clicking here: Test Prints
HP B210 Diagnostic Print

4.c. For a severely clogged ink cartridge (i.e. completely missing color(s) and/or partial jetting of color(s), which cannot be revived by the methods listed above, you can attempt a manual ink cartridge recovery: Clogged Ink Cartridge Recovery (video)

Partially Jetting Nozzles

5. Most inkjet printers feature an "econo mode." Using this setting reduces the amount of ink used on a print and does result in lighter prints. Make sure this setting is turned off if your prints are lighter than preferred.

Poor Print Quality or Smearing Ink (i.e. mixing of colors):
Whenever a printer finishes its document, your ink “rests” or docks usually on the right or left of the printer. Over time, this area can harness a ton of ink mixed with paper dust. This makes a gooey substance that’s can cause big image problems on the paper since every time you print, you run the chance of hitting or docking on this mountain of gooey ink. To clean, we’re not going to use a cleaner, because if you can see a buildup of ink. To access this 'service station' area, simply open up the cartridge access door and the carriage should kick out to the center of printer...using a small paper towel or long cotton swab gently wipe away the ink residue until thoroughly clean (NOTE: you may need to use a flashlight and long cotton swabs to access this area depending on the printer model). 

Additional service instructions available from Inkjet411: Ink Cartridge & Service Station Cleaning