Just relax and strive for right hand fluidity. Just sort of ease your way through it rather than trying to muscle the pick across the strings. Practice ascending and descending equally. Take great care to not let the notes bleed into each other. Also, this is an obvious no-brainer, make sure your left hand is perfectly in synch with your right. It's all very non-mysterious, common sense stuff. There are no tricks, only practice. Don't try to rush your progress and practice slowly and often gradually building up speed with a metronome. Also, for whatever reason, I find 5 string sweeps to be the easiest.
A lot of the cooler-sounding sweeps involve some form of legato playing mixed in. Like, for instance, if you were to sweep a 7th chord arpeggio instead of a triad. You'd probably have to hammer on from the 7th back up to the root.
Also, find chords you like and learn what notes are in them. Then use common sense to figure out the best places on the guitar to sweep/hammer/pull/slide/tap them.
Next try linking different arpeggios. Once again, use common sense when doing this.
Another good idea is to alter the notes of your familiar arpeggio shapes. Even moving a finger a fret up or a fret down can make a big difference. (think of a sensible thing to call the new arpeggio - not something stupid like a major triad with a lowered 4th. look up pitch class set theory or pcset theory on google and you'll find stuff)
Also, if anyone's willing to host images, I could maybe write some little examples, scan them, and post them here.
Here's a lick that I've been using to get myself out of my lack of guitar chops slump with. It's not tonal (although not particularly strident in it's atonality - it even has some 7th chords) and it doesn't "work" over any changes. It's more of a silly prog metal everyone-in-the-band-stops-playing-but-the-guitarist-who's-fulfilling-his/her-duty-to-shred type of licks. Because it's not tonal, I'm going to wantonly abuse the ability to spell different pitch classes enharmonically (I should really be using numbers but that's less intuitive).
These notes are 16th notes (4 to a beat):
Start out picking the open A string and hammering onto the E then the G# on the same string. Sweep the Bb on the D string, Eb on the G string, the Ab on the B string, the B on the high E string. Now pick the octave E on the high E string with an upstroke.
These notes are quintuplet 16th notes (5 evenly-spaced attacks to a beat):
Slide up to and pick the A on the 17th fret of the high E with a downstroke then come back down to the E on the same string with an upstroke, sweep to the C# on the B string, A on the G string, and to the octave D on the D string. Switch your picking direction to downstroke and pick the F# (which you'll have to slide up to) on the D string, sweep the C# on the G string, the 15th fret E on the B string, and the G# on the high E. Now hammer the B on the same string and tap the glorious E on the 24th fret of the high E string with your middle finger.
The rhythm is 2 beats of 16ths followed by two beats of quintuplet 16ths ending on a downbeat. Make sure your quintuplets happen in the same time span as your 16ths and that they're played evenly.
... I see where your comming from with the "make up your own shit" stuff.. for some reason I understand the guitar more intuitively through sweep-esque patterns.. so I think it is really going to help me add some flair to my playing... I have been doing the metranome practice a lot... I started with 3 string patterns and have now started some 4 string patterns... hopefully I find 5 as easy as you do 
