Om Swami
How should I do seva so that it is real service to the other person?
Serve in their way, not yours
Seva (selfless service) is done in the other person's way, not your own. If you serve someone in your own way and not theirs, do not serve them, however much hardship you take on.
If you are serving someone in your own way and not in their way, then do not serve them. However much hardship you go through, seva is that which is done in the other person's way.