Festive clothing fails for boring reasons — it itches, it is too warm, or it cannot be undone quickly when a bathroom is needed urgently.
Line everything
Raw silk and zari are beautiful and abrasive. A cotton lining between the fabric and the skin is the single change that keeps a child in an outfit past the first hour.
Elastic over drawstrings
A drawstring that a five-year-old cannot retie alone becomes your problem four times in an evening. Flat elastic with an internal button adjuster solves it.
Pack the change of clothes anyway
Everyone knows this. Almost nobody does it. The photographs happen in the first hour regardless.