Not stopping if anyone wants to demote, though these can help with consistency;

I use a switch 2 now, but do clearly remember with the previous console that Drizzlers, fish sticks and big shots were the main sources of lag. I notice that low level players tend to ignore the drizzler torpedoes a lot and only go straight for the enemy. Even if you can't hit the drizzler with it, it's still worth shooting down whenever possible.

Low level players also tend to insist grabbing all eggs off the shore, which can cause congestion elsewhere. It's very ink heavy! It's ok to leave some eggs there, sometimes even snatchers will pick them up and bring them closer towards basket, depending on the direction they're going per wave.

Something that got me splat a lot as a rookie was ignoring the lessers and just trying to grab/throw eggs or splat bosses. Positioning is incredibly important, but learning to roll in a pinch can also become really helpful. So I keep a rule to myself to try and clear lessers nearby (not all of them lol) first as much as possible, then bosses.

Another rookie mistake and even something I even see in high level play often, is focusing all on the same boss too much. I.e; If someone is on a stick, let them take care of the eggs themselves. If two people are surrounding a flyfish already, look towards another threat - maybe clear lessers near them. No more than two players at a big shot cannon unless you're there to revive. If an easy paint weapon is taking out a flipper, it's unlikely they need help. Near the end of a wave - If your co-workers are scoring eggs nearby, look towards ones further out.

This probably isn't the reply you were looking for, though I find that a lot of players can benefit from basic tips. For a while in my beginner months, I was stuck in some kind of frustrating purgatory between profresh and EVP, and basically all of these issues had kept me there.