In Brazilian Jiu Jitsu, the order of the day is pretty much always to use what works, period. At the end of the day, it doesn't matter whether a move looks flashy or not, and generally speaking, most effective moves don't really look like anything special. Then there are moves like the "Shaolin sweep" (so named after Vitor "Shaolin" Ribeiro, a black belt world champion who rose to prominence in the late 1990s in sport BJJ). If you hit this at the gym, you feel like you're on top of the world, and if you hit it in a tournament, people are bound to take note. Nevertheless, the sweep can be a very effective piece of a game, and under the right circumstances, this can become a high percentage move for you.
The Basic Mechanics
One of the easiest ways to start working on this sweep is from scissor half guard, a position that can operate as a gateway and hub for lots of different types of guard. Start by trying to sweep your partner backward by cross-gripping the sleeve and gripping the pants with your free hand, an attack that is relatively easily defended when your partner simply drives their weight forward. This is exactly the reaction you're looking for. Keep your shin (the top of the "scissors" you've created), but allow your leg to retract, creating a "loaded spring" type of scenario. Meanwhile, use a "bicep curl" to elevate your partner's knee off the ground, and position your sleeve hand so that you can pull your partner off balance. It is imperative that their sleeve hand isn't able to post on the ground, so make a circle with your grip so that their hand tucks harmlessly under their body, preventing any sort of base on that corner. Now, just look to your left (away from the sleeve grip), and roll over your shoulder as your partner falls.
Shaolin Sweep as a Kimura Counter
Another very simple way to start using the Shaolin sweep -- particularly if you are already using the floating pass Kimura stuff -- is to allow your partner to grab a Kimura grip on your arm from half guard. Once they have this grip, hide your arm inside of your thigh, making sure they can't simply rip the hand free and finish the shoulder lock or armlock. From here, although they have you sort of stuck holding your thigh, it's important to realize that they're also locked in to holding onto the Kimura grip. This means you can take advantage of their limited base. Start by gripping their "base" foot (assuming they are using a hip-switch position),and follow up by rotating your hips to the side, away from your partner. As they slide across your body, use their momentary weightlessness to shoot your hips up in the air, elevating them above you. As their weight begins to drop, just look away from them as before, ensuring that you roll across your shoulder, and not across your neck. You'll finish on top, in prime position for a Re-Kimura.
From the Hip Switch
You can also hit the Shaolin sweep from the hip-switch position itself, without any sort of Kimura grip. This time, start with your partner's arm underneath your armpit, with their weight holding down your sternum (some people call this the "Twister pass"). First, grab their foot or lower pants leg with your free (right) hand. You might need to use the previously mentioned hip rotation technique (get onto your side, and your partner will end up draped over you) in order to get the initial grip. Next, take away one of their "table legs" by pushing their arm down with your left hand, keeping your partner's hips switched and keeping their hand unable to post. Finally, look away from your partner, making sure you roll over your shoulder, bearing their weight somewhere other than on your neck!
Which Shaolin sweep variation works best for you?
The examples above for the Shaolin sweep should give you ample material so that multiple approaches can be used in figuring out the basic mechanics. Once you figure out one way to do this sweep, the others are very likely to follow in short suit. Be patient, as this rather nonintuitive method of sweeping may take some time to get down, but the skills will remain with you over the years, and you'll continue to find ways to use the "hips high" concept stressed above. As always, let me know how these techniques work for you!