Quick answer
Provide a complete, truthful disclosure; an asset can matter even if it is uncertain, jointly owned, or not cash.
Do now
List accounts, vehicles, real estate, businesses, digital assets, expected refunds, legal claims, and other interests for your lawyer to assess. Explain disputed ownership and recent changes. Retain supporting records.
Watch for
Exempt property still needs proper disclosure and exemption treatment. Omissions or concealment can threaten the case. Do not decide an asset is irrelevant because you think it has little value.
Official sources
US Courts — Chapter 7 Basics, US Courts — Discharge in Bankruptcy, US Courts — Bankruptcy Glossary.