2step (garage) takes the general kick snare kick snare pattern but it's the detail and embelishment that make it funky.
firstly you often overlay four offbeat hats (so shifted an eighth from the main four beats in the bar), that date from house/techno. These are often pitchbent down between the third and fourth beat
Then you swing the hats that fall outside of the main four beats and four-offbeats. Then there's loads of other embelishments you can add, double kicks around the first beat, or delay the kick on the third, by an eighth. these can be pitchbent in places too.
Or you can push the second snare on the fourth back by an eighth.
And you can fill the hole between the second and third beat with additional percussion.
All that said, i can do all these and more but somehow geniuses like El-B make it sound yet funkier by some magic tricks that have decived my ears for the best part of seven years... but no mind, it makes me happy that there will always be some more drum magic out there to learn.
Following on from Blackdown... Some have what I would call "flat" snares, ie on the expected (in terms of backbeat syncopation) 2 and 4 beat... and really swung hi hats/shakers (ie- subtly fluid in terms of placement just before or after the quantised position by a tiny amount to give a live-ish feel). But the best stuff (and this is something which Grime certainly used to excel at) has them at funky angles, slightly before or after the expect 2 and four, giving it this kind of mutated cubist snap effect. The best dubstep also does this, and it enables crazy syncopation, especially if the music (basslines especially) is synced up to coincide rhythmically with the "off"-placement of kicks and snares, that really amps up the jitteryness (almost taking it into jazz territory of skittering anti-funk).
Another key part of 2-step is having space or gaps in the beat and music, little stops which create an additional level of unexpected rhythm-drive. Combined with the "off" snares and basskicks this makes this kind of music unbelievably fascinating.
But really its all in the shakers/hi hats, they are the stitching that ties the rhythm together, it stands or falls on how well they interact with the rest of the beat, giving it space and a sense of drum-narrative, connecting the kick to the snare in that extra-itchy manner... Theoretically a half step pattern ought to give even more space and room for hi-hat patterning (given the additional space involved) but not many have followed up this angle...