I used to feel bad about saying no because my nature is to not disappoint people.
Luckily I’ve (mostly) gotten over that :D.
I just say “no thank you.”
There’s no comeback, argument, or workaround for it, and it’s polite.
And I NEVER say “sorry”, because I have nothing to apologize for. Women love to use that word when it’s not needed, and I feel like it dilutes it. Sorry should be for when you’ve done something wrong and you need to apologize. Women use it to temporize and it makes me nuts.
ETA: Once I remembered someone was pressuring me to donate to their friend’s kids whatever whatever, and I said, “feel free to donate $20 in my name if it’s that important to you”.
She never asked me for stuff again, or invited me to her Trapped In Your Home Must Buy Pampered Chef/Silpat/Crap Of The Month parties, either.