Start with paddle tailed plastics.
These give confidence because they have a built in action.
Fish them in area's where up to 20g heads are suitable and try to choose somewhere with
ocean motion, like a cross current.
slow roll them over the bottom, or lift and drop, burn and kill etc...
slow rolling is steady retrieve with as much bottom contact as possible.
lift and drop. cast, sink, wind up slack and lift the rod back like you are striking but not so far.
Make it more of a wrist action. wait a short period, wind up slack, start again.
burn and kill: cast, sink, wait, wind FAST as you lift the rod tip for 4 to 6 turns depending upon depth etc
STOP but drop the rod tip towards the lure to ensure a tension relieved fall of the lure. The lure tail will still
kick on the drop and, many fish are taken NOW before the lure hits bottom.
If daylight and calm, watch your line. As a SP falls it will leave a 'V' wake where the line intersects with the falling
lure. If the 'V' stops abruptly for ANY reason other than hitting the bottom. Strike ! A good rod will give you the
tell tale feedback of where your SP is on the bottom, or not and help detect the shy takes often common on the drop.
At night, count down your SP head and work out the takes from that.
If you are getting 5 seconds from a crank to bottom and suddenly you count to 7..Strike !
Strike at everything that doesn't follow a pattern in fact.
Hope that helps a bit.