Swimbaits and twin tails.
I prefer the large twin tails, Kalins or scampis in white or Chartreuse green flake with a large head up to four ounces.
...but I have caught more halibut including a 33 pounder on the 3 inch version in glow green.
Swimbaits I use white, white blue, silver blue, white black and clear red flake when there is squid around, but I'll be honest my largest halibut on a swimbait was only fifteen pounds, and I've caught more fish with twin tails.
The deal is the larger twin tails almost always hook big fish, small fish especially small bass do not mess with them, so when you do hook a fish it's usually a good one. The only issue is that sharks like big soupfins and pinbacks also like them, and I've even caught threshers with them. When sharks hit them they shred them, so if there are a lot of them around (pinbacks school up) you can end up going through a lot of baits rather quickly.
The smaller twin tails are a more productive bait but you get a lot of smaller fish with them. Everything from bass to sculpin to halibut. If bass are thick you can get tired of messing with them, but if things are slow it's the goto bait.
Swimbaits get bit well but the hook up ratio is lot worse for halibut for some reason. I think this is because halibut think twintails are squid and just inhale them where they think swimbaits are fin bait and try to swallow them head first which makes it harder to get a good hookup. I've lost a lot of decent halibut on swimbaits. When I start feeling head shakes I always get nervous because they are often poorly hooked with swim baits and the bait has enough weight they can easily shake the hook.
Take some frozen squid and put small strips on a Mojo Kalins or twintail and you will catch halibut. Sink to the bottom reel a few turns sink to the bottom type fishing and half the time they hit it on the sink.
Good luck, Jim