The lingo can be a bit confusing.
Harling is trolling a fly - usually a wet fly pattern (e.g. a grey ghost or a parsons glory), often most effective at the change of light.
Trout jigging is often done with a string of three flies on a rig similar to a ledger rig
http://www.marine-deals.co.nz/jigs/kilw ... gging-rigs
If you can find the right spot with your fishfinder it can be very effective.
You can just tow a spinner - e.g. a black toby. Often people troll minnow type lures - called Tasmanian Devils or Cobras.
http://www.marine-deals.co.nz/lures-2/k ... evil-lures
Some people run a harling fly on a short race tied onto the hook on the Tassie.
Personally I take the hook and wire out of the tassie and just run the leader through the lure, replace the original hook with a hook that has flasher material on it, add a swivel about 3 feet above the tassie and place a free running harling fly above the swivel.
You can also cast spinners from a kayak to good effect e.g. along channels in weed banks that trailer boats struggle to navigate through.