This way they have a choice to accept the help or not.
I do this too now.
But sometimes I feel I have to look between the lines in whether their no actually means no or is it just their pride talking. It is certainly a fine line as you say. You never know really what to do for the best.
I always tell them not to be afraid to ask me for help or change their mind about allowing me to help.
I also used to say that it would make me happy to be able to help them if I think it is their pride because their pride will want to please someone else as if they are doing me a favour ;)
If I do things that they end up not pleased with I just let them know that it was just to try and make them feel better nothing more or less. I do not want anything back or I do not need their appreciation or for them to feel they have to do something back. It was an altruistic move only :)
I also used to think I did things because I wanted to be needed, to feel useful, as reason for being there. Now I am not so needy I do find myself not volunteering myself so much but I also realised that in most cases I was just being altruistic and most people find that hard to comprehend. :)
I now feel that if I ask them if they need help, it is also ok to accept their decline too and not take this as a personal shun.
I now try to make them feel better by giving them a personal gift or bunch of flowers or a hug instead. That way it cannot be misjudged. :)
Human behaviour is a complicated thing eh :)
Best wishes
Saffy :)