Plenty of options really. Those fish aren't picky. You could start with black woolly bugger type patterns. Try some with weight on front if needed for better swimming action. Just watch out as the hooks will corride unless you have your saltwater hooks. Or you can wash them will after each trip (I rinse my gear, including rod and real, after all salt water trips).
There are also some bass patterns that may be useful. Dahlberg divers are kinda like a plug that dives deeper as you strip it in and has some good wiggle. Maybe worth a try if the wooly bugger patterns aren't working. The tried and true clouser minnows patterns are a no brainer for salt water fishing as well. MANY variations and color and material options to choose from. Great action in the water.
For these flies, I would start with a floating line and 12 foot tapered leader downt about 8lb Max UG tippet. Cast out, let sink as you count down, and when you think you are as deep as you need to be, begin stripping it in. You can try the following retreives and see which gets the most strikes - sometimes the retreive is more important than the fly...
* Fast strip with no pauses - bait fish high tailing it out of there
* Incredibly slow boring retrieve - fish are being shy and not aggressive. Maybe seeing it slowly approach and go by will bring them out.
* Alternate the 2 above - go about 2-4 feet super fast, then slow for 2-4 feet
* Erratic - few quick strips, short or long pause, strip a time or two, pause, etc (I probably do variations of this the most)
Nice thing about the clouser minnow patterns, is that they are super easy to tie, and super cheap. Hook, dumbell or bead chain eyes, and some bucktail, bunny fur, marabou, etc of various shades. A little flash is good. You can whip these out super fast and have a box full of colors and varieties that will catch cutties, salmon, bottom fish, bass, etc all day long...
Look up some youtube videos on tying them. Remeber, it is kinda like cooking, the recipe is helpful, but feel free to get creative and change things up once you understand and master the basics.