Constitutional arguments are routinely forfeited by being raised late or framed loosely.

Raise it in the trial court. Even where the argument seems futile because controlling precedent forecloses it, preserving it is what allows a higher court to reconsider. Note the argument, cite the controlling authority, and state that it is preserved for further review.

Be specific about the provision and the theory. A due process objection does not preserve an equal protection argument; a facial challenge does not necessarily preserve an as-applied one, and the reverse is also true.

Notice to the attorney general. Statutes and rules generally require notification when the constitutionality of a statute is challenged, and failure can delay or defeat consideration.

Build the factual record. As-applied challenges depend on facts, and appellate courts cannot receive evidence. Legislative history, comparative enforcement data and the burden on the claimant must be introduced below.

Ripeness and exhaustion. Land use takings claims, in particular, require a final decision. Filing early results in dismissal without prejudice and the loss of years.

Standing. Plead the injury with specificity, and for prospective relief plead the concrete likelihood of future injury.

Preserve alternative grounds for affirmance if you prevailed below, since they may be urged without a cross-appeal.