There's a guide on spigot that helps in configuration your files that can sometimes help in some lag One thing I'd recommend first is adding a world border (using the plugin) then rendering it out another is using PaperMC if you are using bukkit/spigot, it doesn't change aspects from spigot but does add more options so you can tweak it further and allow for some tps savings
If you're too lazy to change up your yml server files you can use mine as it doesn't affect survival in a noticeable way, just helps.