Customizing each post’s “Read the Rest of this Entry”

Hello.

I am a novice coder, relatively new to wordpress so bear with me here.

I’ve read several posts on how to change “read the rest of this entry” universally.

I was wondering how I would go about doing so for each individual post.
ex. for one i might say “See more diagrams below the jump!” and another i might want to say “Read about my opinion on this matter”

Thanks,

cleancutmedia
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