Argh I just can't grasp slap (self-taught)

wow I just noticed there are like 8 topics on slap bass! o_o we should have an "official" thread and delete the rest...
I need someone to correct my mistakes. practicing with bad form can't be good imo, cause then you have to lose your bad habits
I watched one bass video before(can't remember if it was Larry Graham or Louis Johnson), but he said about practicing SLOWLY with a METRONOME first to get a good foundation and slowly speed up.
Most of us just want to do it fast so that we can show off or make it sound right(he said it too).
Slow and Steady!