How do I transfer crypto between Coinbase wallet & Coinbase wallet?

Could you kindly explain the process to me? I'm a bit confused about how to transfer cryptocurrencies between two Coinbase wallets. Could you please provide step-by-step instructions? I'd appreciate it if you could also clarify any potential fees or limitations involved in such transactions. Additionally, is there a specific time frame during which these transfers are most efficient or advisable? Thank you in advance for your assistance.