I was using 6 pound mono, a size long shank hook and no sinker. Small pieces of bread crust, no more than 1cm square. Flick it out like you are throwing a Frisbee.
Now for the hard part. You need a slight breeze blowing from behind you, try throwing that into the wind and you won't get anywhere.
For windier conditions, a small bubble float, half filled with water will help casting conditions. For really windy conditions, the gars probably won't be biting.
Gars will swim down several metres, but usually swim very close to the surface.
Bread is the main bait I use, though have caught them on dough, squirt worm pieces, small pieces of soft fish flesh, and the occasional ones on a whiting hook and nippers, when fishing shallow water for the whiting.