Make sure you use good quality mainline, leader, and tie good knots so you know you can pull on the fish without worrying about him breaking off.
Make sure you use good quality hooks so you know you can pull on the fish without worrying about the hook bending out.
Make sure your hooks are sticky sharp so you increase the chances of the fish getting hooked.
Make sure to check your hooks, knots and line condition regularly, don't assume everything is fine.
When using barbless hooks I have found it helps to curve the point ( claw ) and to offset the point slightly.
When playing the fish, try your best not to ever give the fish any slack line as barbless hooks can and do fall out easily and keep your rod tip up.
When the pin pops on the rigger the fish has some slack line until you get the belly out of the line ( especially when fishing deep). Pick up this slack as quickly as possible, some people speed up the boat for a bit until that slack is taken up.
If you have a large fish and he runs a long way chase him down with the boat ( don't give him any slack ) rather than drag him all the way back to the boat. Better landing % and less chance some bozo will run over your fish and break the line.
If you have a large fish make sure to clear the rest of your lines and downriggers out of the water so the line won't get tangled when the fish gets to the boat.
Have a big net ready, net the fish when he is ready, scoop him head first into the net.
Don't put the net in the water until the fish is ready, many large fish are lost when people panic and try to get them in the net before they are fully played out.
If you manage to do all of the things listed above you have done all you can do to put the odds in your favour.
Unfortunately you are still going to lose some fish mostly because of how the fish is hooked.
Make sure you use good quality hooks so you know you can pull on the fish without worrying about the hook bending out.
Make sure your hooks are sticky sharp so you increase the chances of the fish getting hooked.
Make sure to check your hooks, knots and line condition regularly, don't assume everything is fine.
When using barbless hooks I have found it helps to curve the point ( claw ) and to offset the point slightly.
When playing the fish, try your best not to ever give the fish any slack line as barbless hooks can and do fall out easily and keep your rod tip up.
When the pin pops on the rigger the fish has some slack line until you get the belly out of the line ( especially when fishing deep). Pick up this slack as quickly as possible, some people speed up the boat for a bit until that slack is taken up.
If you have a large fish and he runs a long way chase him down with the boat ( don't give him any slack ) rather than drag him all the way back to the boat. Better landing % and less chance some bozo will run over your fish and break the line.
If you have a large fish make sure to clear the rest of your lines and downriggers out of the water so the line won't get tangled when the fish gets to the boat.
Have a big net ready, net the fish when he is ready, scoop him head first into the net.
Don't put the net in the water until the fish is ready, many large fish are lost when people panic and try to get them in the net before they are fully played out.
If you manage to do all of the things listed above you have done all you can do to put the odds in your favour.
Unfortunately you are still going to lose some fish mostly because of how the fish is hooked.