No, thank you.
Thanks, but no thanks.
That sounds lovely, but no.
Not right now.
Not for me.
It’s not an option.
I won’t be able to.
It won’t work for me.
I have a conflict.
I have plans.
That’s a negative.
I’ll have to pass.
I have other things planned for that time.
My project list is already full for the month/year.
What a great idea! I wish you luck with it.
Sounds interesting… Let me know how it goes.
I don’t have the resources for that.
Now is not a good time.
I have other commitments.
I’d rather not.
I appreciate the offer but I can’t accept.
I’m honored, but unable to accept.
I’m not taking anything else on right now.
I’m staying focused on _____.
I couldn’t give it enough attention.
That wouldn’t leave me time for my other commitments.
I’m saving my space/time for other projects.
Thank you, but there’s no more room on my to-do list.
No can do.
Keep me posted on your progress.
That’s not ideal for me.
That’s not a fit for me.
No more commitments for me.
My plate is full.
My calendar is full.
My brain is full.
It’s a great cause for someone else.
That’s a wonderful opportunity, but not for me.
That doesn’t match my skill set.
That doesn’t work with my interests/focus.
Sounds like you will do a great job on that.
I won’t be there.
I can’t make it.