I have an acquaintance who tried to constantly use me by starting her sentences with 'can you do me a huge favor?' At first, because I thought we were friends, I'd help her. Now, after getting burned and put on the back burner in her life, I've learned to 'just say NO'. I choose not be used or abused. She is no friend.
Same thing with sewing jobs - just say no - people just don't want to pay for something you put so much time and effort into.