How high should I set slippage?

Excuse me, but could you please elaborate on the topic of slippage in the context of cryptocurrency trading? As a trader, I'm always looking to optimize my strategies and minimize risks, so I'm curious about how to appropriately set the slippage tolerance. Could you offer some insights on what factors should I consider when determining the ideal slippage level for my trades? Additionally, could you explain how slippage can affect my trading outcomes, both positively and negatively? Thank you in advance for your expertise.