Twibright Six Cream, an open source skateboard bearing lubricant

Tools needed

Old bottle cap or larger container if you want to produce larger quantity
Toothpick

Material needed

Medical grade petrolatum a.k.a. Vaselinum Album a.k.a. white petroleum jelly
WD 40 or another similar general purpose spray oil with anti-corrosion and cleaning properties

Procedure

Put a bit of the vaseline into the cap
Add a bit of WD40 and stir until it's homogeneous
Repeat until you get a consistency of honey
Clean the bearings according to the manufacturer recommended instructions. I use stain removal gasoline (petrol, benzin) to clean the insensitive parts and rubbing alcohol to clean the rubber sealing that can allegedly blister.
Apply into the clean bearing with the toothpick. Don't fill completely, just until the inner mechanism is slimey
Wipe the Twibright Six Cream from the outer surface of the bearing if you contaminated it
Reinstall the bearing shield if any
Wipe the outside dry again
Spin the bearing through to see how wonderfully it turns :)

Tweaking

Unlike commercial available lubricants, with Twibright Six Cream a continuous spectrum of consistency adjustment is available. Use a bit more WD40 to get a faster lubricant for racing, which will however last shorter. Or use more vaseline to get a thicker lubricant that will not spin so fast, but should last longer.