at least, make it look like you can solve it incredibly fast
a small preview of what it looks:
Step 1: Learn to Solve the Cube
Step 2: Notation
Now you know how to actually solve the cube you probably know the notations
I'll go over it again just to be sure
-The front face is labeled F.
-The back face is labeled B.
-The top face is labeled U.
-The bottom face is labeled D.
-The left face is labeled L.
-The right face is labeled R.
-If a letter is labeled by itself, turn the face clockwise as if you were facing it.
-If a letter is labeled with an ', then turn the face counterclockwise as if you were facing it.
-If a letter is labeled with a 2, turn the face 180 degrees(twice).
Image borrowed from eLeet until I've shooped my own, check his instructable for solving the cube while you're at it
Step 3: Scramble and Solve
Because you probably want others to see you scrambling the cube the scramble is large (17 moves) to make it "believable", you either have to learn it by heart (or by hand) or you have to have it written down somewhere, I recommend you to put it in your mobile phone and say it's a scramble generator (as if the scramble is random)
the code: D L2 B2 L2 R2 F2 R2 U2 R2 D' U' R' B F L' D R2
the solve is shorter, you can learn it by heart and to make others believe it's an actual solve you have to: R2 D' L' F' B' R' U'
the solve has to be done with the pattern in the image facing you
good luck on learning it and showing everyone
They'll think you're a genius