Step 1: Clear away all dust and debris using the air duster. Clear out any dust from the print head fans. I usually spin the fans up to 100% to check that they are spinning freely and are no obstructions. These can easily get clogged by dirt, dust and bits of filament.
Step 2: Remove all filament and check the extruder to ensure that there isn’t a build up of filament debris on the main gear. I recently found I was getting inconsistent extrusion and it appears to have come from a build up of muck on the gear.
Step 3: Grease the z-axis rods and move the z-axis to the top and then back down again to ensure a good coverage of grease.
Step 4: At this point I will reload filament and extrude about 50cm of filament to make sure it is all flowing well.
Step 5: I am obsessed with having a level bed so before levelling I use two 15cm 3d printed rectangles to make sure that the x-axis carriage is level on both sides and make a small manual adjustments of the z-axis.
Step 6: Clean the build plate
Step 7: Clean any remaining filament (carefully) from the nozzle
Step 8: Level the bed manually.
Step 9: Level the bed again!
Step 10: Print a test print.