Make the Rubik's Cube Slide Faster

Want to solve your Rubik's Cube faster, but are cursed with a stiff, slow-turning cube? Here's a quick fix to get your Rubik's Cube turning smoothly.

Steps

Turn one side of your cube about 45 degrees so that the corners poke out over the other sides.
Pop out one of the middle cubes. Sometimes, it helps to put a screwdriver under that middle piece and pry it out.
Place a finger full of Vaseline into the hole. Too much will make your cube too greasy and gross, too little won't work.
Replace the middle cube. The cube should just snap back into place. It may use some force but try angling the piece in different ways if it doesn't work
Make some cube turns to work the vaseline in and around your cube.
Repeat on different sides until you are satisfied with the turning of your cube.

You can put silicon spray in your cube to make movements slicker.
You may have to remove more than one middle cube from each side to ensure that the Vaseline gets in every crack.
Astro Glide works nicely too!
Unfortunately, even though Vaseline works well in the short term, it's NOT recommended as a long-term solution for Rubik's Cube lubrication. The Vaseline may eventually soften/partially dissolve the plastic inside the cube. If you want a long term lubricant you can find Rubik's cube specific lubricant on "speedcubing stores" online.