A civil complaint has one immediate job before it can do anything else: survive a motion to dismiss. That means it has to state a legally valid claim with enough factual detail to be plausible, not just alleged.
Plead facts, not just legal conclusions
Simply asserting that the defendant 'breached the contract' or 'acted negligently' isn't enough on its own — the complaint needs specific facts that, if true, actually support that conclusion.
Match every claim to its legal elements
Each cause of action has specific elements that have to be pled. Skipping one — even if it seems obvious from context — gives the defense a clean argument for dismissal on that claim.
Jurisdiction and venue aren't afterthoughts
A complaint has to establish why this court has authority over the case and the parties before it gets to the merits — gaps here are an easy, purely procedural way for a case to get knocked out early.
Ask for the relief you're actually entitled to
The prayer for relief should match what the claims actually support — damages, injunctive relief, or specific performance, stated clearly enough that the court knows exactly what's being sought.
Anticipate the obvious motion to dismiss arguments
Reading the complaint the way opposing counsel will — looking for missing elements, vague allegations, or jurisdictional gaps — before filing is the most effective way to draft one that holds up.