One thing that many low-mid level pilots struggle with is vision.
Remember that for the majority of ships, below and above are huge blind spots. People are trained to try to go as high as possible (for balloon popping/countering balloon popping), and thus scan the sky carefully.
The biggest blind spots bar none is right below them, and with a open air ship (mobula, squid, both of which also have fast balloon speed), you can sneak up and wreck people by hugging the dirt and staying below clouds, esp if you have a spotter partner with you.
Hydrogen is an essential part of that strategy as well.
Like people stated before claw is pretty overpowered, doing negligible damage and providing ridiculous turn speed, even on a galleon.
One thing to consider when trying to create your own "meta" is arc spread. There are guides on this, but remember that you want to be able to maximize gun coverage (obviously), and the most "powerful" weapons are not necessarily the best used in conjunction. Similarly, when fighting a ship with certain arcs, know what to do to dodge them.
Here are some things I noticed about each ship.
Junker - This ship requires good communication with crew. General "division of duties" is, 3 engies. 1 engie front gun and hull (you can hit through the little wooden panel while standing on the ramp leading down), 1 engie top deck guns + balloon/turn engines. 1 engie bottom guns + main engine. In order to fly a junker successfully, you need to rely on quick disableand overwhelming firepower with 3 guns. Your armor is huge, and you must kill them before it goes down because you have 0 hull hp. Contrary to intuition, this means do NOT ever focus on repair. If you are needing to repair you are either fleeing or dead already. The point is to never stop firing. In order to get triple arcs, you need to position the enemy at 10-11 or 1-2 o'clock. You need wide firing arcs, such as carronade, banshee, flamer, gat. Correct me if I'm wrong but I believe triple artemis is no longer possible with the nerfs.
Pyra - ram ram ram. Regardless of your guns you always want to ram. The pyra has the best ram in the game, and with kerosene/moonshine it absolutely wrecks (no impact bumpers needed). You can sprint in with double gat even if you wish, and just ram them continuously. Remember though that your prow is above the gunners in front of the balloon, so aim low if you want to ram their hull. Engie on balloon/left gun, gunner on right/jump down for side, main engie on bottom deck. You can repair the main engine from below just by looking up.
Goldfish - One of the weakest offensive ships (unable to ever get more than 1 arc on main target), it requires a good combination of turning and positioning (possibly ramming) to do well. Fortunately it is extremely maneuverable to accomplish this. Always have a claw, and be able to count in your head the time it takes for your front gun (esp hwacha) to reload. On larger (longer) ships it is possible to flamer/gat + hwacha. Since you ever only have 2 guns max on target, gunner will swap between guns as needed with 2 engies splitting engines/balloon/hull/shooting.
Squid - never be seen. Come from above or below, never dead on. Flamer is extremely painful on this. Always aim for the engines first, then guns, then either squat them to death (triple flamer squid if you like, so you can spin and flamer while sitting on them), or stay on their butts. Repair the engines before anything else. A nonmoving squid is a dead squid.
Galleon - many favor a sniping side and a short range side. Not much meta here, just sheer firepower. Make sure you have good spotters, once a galleon is disabled it is very painful to save. Gunner + engie downstairs, main engie upstairs, pilot is in charge of the balloon.
Spire - by far the squishiest ship in the game, but 4 front facing guns (possible to get all 4 firing). You need long range spotters and good gunners, or close range sneakiness. If you're seen first, and you're not immediately shooting, you lose. NEVER try to run, always fly backwards, or you will immediately lose. Better to stand and fight. Generally speaking gunner is on main gun, engie downstairs for second gun + balloon, engie upstairs for right gun, pilot fires top left gun. There is a chute (and ladder) to quickly get between the decks in the middle of the ship. Pretend you're a fireman (or stripper...) and slide down. Always shoot first and repair later. Similar to the junker, the main idea is to kill them before they kill you.
Mobula - Be aware the mobula "floats" more than other ships. It feels like flying across ice, or as some say like flying a balloon. So remember that when attempting quick maneuvers. Has the fastest balloon action in the game, so use this to your advantage to engage/escape/dodge. No guns near the pilot, so you're looking generally at 3 guns max on target. Gunner will take top deck guns, while each engie picks a side and the bottom gun associated. One of the harder ships to successfully repair, it is an offensive ship so concentrate on firepower before repairs.
EDIT: one thing I forgot to mention that a lot of pilots don't do is fly backwards. You have full speed backwards, and flying backwards has two major advantages.
One is they can't shoot your engines, allowing easier escape.
Two is you can shoot at them with your front guns while escaping.
Its actually not hard to fly backwards (except on certain ships like the pyra, where your view is completely blocked). You do NOT need to reverse directions while turning. While looking backwards, "left" will still go left, "right" will still go right. Think of yourship as being on the rim of a circle and you'll see why.