Me personally...
140 bpm
1/16
Kick on the 1st
Snare on the 3rd
(or if it's a particularly chilled song I put the snare on the 4th)
Like this:
K,--,S,--,K,--,S,--,K,--,S,--,K,--,S,--
or this more chilled alternative:
K,--,--S,K,--,--S,K,--,--S,K,--,--S
After that, I add in additional kicks where it sounds right making sure that the placement suits the song (for example a dubstep track similar to Coki's - Spongebob, I would add a kick on every bar, to provide support and movement for the consistent bassline.) Whereas, a chilled track like Cyrus & Random Trio's Bounty, would have the kicks sitting in a rhythmic compact style that uses swing over a longer time period that keeps to the classic formula like this:
K,--,S,--,K,K,S,--,K,--,S,--,K,K,S,--
Of course this is extremely simplified, you shouldn't alway keep your drums quantized, let them sound natural. And experiment. Try layering different kick and snare at different volumes, ghost snares are the Don!
EDIT After reading the question and not just the title, the key to that lush half-speed dubstep drum sound, is not the kicks and snare, but Hi Hat placement and other percussion. The trick is to have 90% of the Hi Hats and other stuf inbetween the kick and snare, and the second gap (between snare and next kick), to be left almost, if not empty.
KICK,-----,-----,-----KICK,-----,-----,-----
------,-----,SNR,-----,-----,-----,SNR,-----
H,--,H,H,H,-,-,-,-,-,-,H,--,H,H,H,-,-,-,-,-,-
(very quick diagram, excluding genuine open & closed hi hats, cymbals etc.)