As a swim parent, sitting in natatorium seats looking down at swim meets for long days on end, I learned something I never truly appreciated as a swimmer... one of the best ways to find ideas for improving your own swimming is also one of the simplest - Watch.
I don't mean watching your friends swim and supporting your team (though you should always do that, too). What I mean is that you can learn a lot by watching other swimmers.
Watch the swimmers that excel... the ones that consistently overperform at one event, or at one stroke, or at everything. Really look at what they're doing. Is it different than the other swimmers? Is it different than what you do?
And if it is different, is that something you could try to see if it helps your performance?
Break it down. Are their starts different? Their turns? Their breakouts? Their stroke? When are they breathing? How often? Where are their feet when they kick, and how are their hands entering the water?
You may not benefit from everything you see, but it can give you ideas for new things to try and might give you a big insight that will help you perform better your next meet!