LFO on the cutoff is usually just one part of the bass patch. You'll also want to experiment with the resonance of the filter, adding effects to the bassline (distortion, etc.), and then just careful EQ tweaking as well. What synth are you trying to make a wobble with? Some are much better than others.
Also, consider trying to take a bass synth but cut all the actual low frequencies out of it, then modulate the cutoff on that. Add the sub frequencies back with a separate synth doing a pure sine wave or something, then perhaps compress the two together at the end.
Those are just a couple of things you can do--a lot of wobbles are made in ways that don't involve a filter at all (FM synthesis, for instance). Keep poking around, and I'm sure someone else will chime in here soon.