Vitalik Buterin recommends adopting features like "transaction simulation" to enhance the security and user experience of Ethereum wallets and smart contracts. The core ideas include: users first specify their on-chain intent, then review the transaction simulation outcomes before clicking "OK" or "Cancel"; this can be combined with spending limits and multi-signature approvals to ensure that intent, expected results, and risk limits are aligned; the goal is to make low-risk operations easier and high-risk operations more difficult; user intent definitions can be extremely complex, and there is no perfect security solution. A good approach requires users to specify their intent through multiple overlapping methods, and the system only executes when there is consensus; both security and user experience revolve around user intent, applicable to wallets, smart contracts, operating systems, and hardware. (Cointelegraph)