Good point!! 
We fish offshore in 5 - 50m water and and as yet haven’t really thought of targeting a species - anything legal will do! Though Snapper are the fish of choice. 
The bombs I buy are either salmon or mullet based. I tried making my own with chook pellets and tuna oil....

for snapper, mussel burley is a pretty good choice too.

I don't use much burley myself because I usually drift fish with soft baits.
But some of my friends use burley bombs with good success.

If you're fishing in shallower water, less then 20 meters, it's best to tie the burley higher up - best right next to your boat.
Then the current can take it out further, with small pieces slowly sinking to the bottom.

In deeper water it's best to tie it about half way down the anchor line.

If you have leftover fish frames, mussel shells or other smelly stuff you can slowly throw it over board into your burley trail for extra attraction. Catfood is supposed to work pretty good as well and is reasonably cheap.

Once you setup a burley trail, you have to be very patient and wait for the fish to arrive.
It could take an hour or longer of constant burleying. There also needs to be a good current flow to take the burley out.
So best to be at the spot two hours before the best fishing times and start the burley trail as soon as you arrive.

Mark - thanks for this! 

sure thing 😊 hope it helps somewhat.
Whereabouts are you fishing?

We are based out of Gulf Harbour so fish around Kawau, Flat Rock, Tiri, Noises .....been fishing with baits and only just experimeniting with soft baits jigs etc.....

Great area to fish in. During winter time it's best to fish close to rocks and reefy areas.
I used to catch some pretty decent snapper just near Te Haruhi Bay at Shakespeare Regional Park.
A few hundred meters South of the Rocky Ledges on the East end of the Bay. Best during major times (usually low tide).
Might be worth a try for you and it's close by Gulf Harbour. Another good area is just about 2 km straight out from Stanmore Bay. Caught my biggest snapper out there.

If you're just getting into soft baiting give those 5 inch gulp lime tigers a go.
They are my favourites and catch most of my snapper. They work best if you got a good drift going, either from current of from wind. And you have to make sure that they are hitting the bottom.

Berley can work pretty good with soft baits too.
You could attach the berley to an anchor with a buoy or float and then drift past it.
Or you just drift around with the berley bag hanging over the side of your boat.

Let us know how you get on with the burley. 

Out today at 0800 - theoretically not near a bite time till around 1000. Saw some good fish on the sounder lurking down-tide of s pinacle in 25m. Got 3 pannies. 
Moved out to near Shearers ....drifted but nothing doing...went on the sounder hunt again and found some (2) around pinnacles between Shearers and Shag Rock. 
Moved into the Tiri Channel at 1100 in 25m of water 14 deg C...Kina burley. Some small 25 to 28cm but then as the tide picked up so did the fish. 
Ended up with the total of 13 Snapper 35 to 46cm. 
They were not really biting just sort of chewing on the baits in fact the last and largest one my wife had been holding my rod and handed it back saying there had been a couple of bites but i was probably out of bait - nope big old Snapper just lying doggo! Too sleepy to fight till he saw the boat! 
Great day out and freezer full which is good as I think weather is about to sock in for a few days again. 

great fishing, well done. Sounds like it's gonna be fish for dinner for a while now :-)

Where did you get the Kina burley?
Did you try any soft baits this time?

Tried the dog food...no good