Set up a helper that already knows you
Reach for this when you're tired of explaining who you are every single time.
I want you to act as my personal assistant for [what you'll use it for]. Here's what you should always know about me: [your role, your style, who you deal with, anything that saves me repeating myself]. From now on, keep this in mind for everything I ask. First, tell me back what you understood so I know it stuck.
In Claude this lives in a 'Project', in ChatGPT it's a 'Custom GPT' or the 'personalize' setting. Both are just a note the AI reads before every chat, so you set it once and stop repeating yourself.