Well, Sympathy certainly is a challenge to write well, but I can find an example here and go in detail:
[Start of example]
“I’m going to be frank, with you, Drew,” his father began, “Despite the fact that you partake in the feminine sport of coordinating, you’re an exceptional trainer.”
Drew’s eyebrows raised in shock. His father was actually approving of his prowess? But no, Drew thought, there had to be something up his sleeve.
“I saw your battle yesterday and was dazzled to find out that you weren’t a complete lost cause. Not that I thought you were,” he continued, Drew staying quiet. “You see, I never lost track of you. You think you ran away, but I’m sure even you know that the contest business is a gloriously media-centered occupation. Everytime you ever competed in a contest, every ribbon you won, we knew about it and watched you do it.”
Drew gulped. So, his father was not here only because Jack spilled his location – Greg knew all along where Drew would turn up, and what better place to disrupt the atmosphere than at the grandest of all Grand Festivals?
“However, you still coordinate, and that’s a problem,” Greg continued. “You see, I wanted you and Skeet to compete for my business. I wanted to see which one would be the strongest, yet the most knowledgeable of the battling realm. Both you and Skeet possess great power in that, but unfortunately, you have no badges to prove it.”
“So? I don’t care about your business or whatever you do. I’m not interested in battling the whole way down my career, nor do I care about collecting badges. Just accept it-” Drew answered, but Greg cut him off with a wave of his hand.
“I don’t mean to lead you to believe I want you to take over my business…I can’t quite trust you with that, yet,” Greg said with a smirk, “What I want is for the two of you to help me in creating a monopoly in the battling realm and get trainers the coverage they need to be successful.”
Skeet jumped in on this, “Yeah, it’s not fair frickin’ coordinators all become celebrities, but most trainers don’t get any recognition. The only ones that really get it are the Elite Four.”
“Which is where you come in, Drew,” his father said, trying to play the compassion card. “You already have recognition in the coordinating world – your influence could greatly help us reach our goal, especially if you became a trainer on top of it, like a middle ground.”
“What exactly are you planning?” Drew challenged. He didn’t like where this was going.
“That will all be revealed to you in time,” Greg answered, aware that this might cause conflict, and that the proposition he was rambling to Drew was not what they needed him for. However, his true plans, the ones that needed Drew's status and brains, would have also caused conflict.
“And if I refuse?”
“Oh, you can refuse…but there will be consequences,” Greg threatened. “After all, I’m sure you wouldn’t want anything bad to befall your little girlfriend. Or, maybe, we could buy out the Orchida dome right now and turn it into a battling arena, causing the last Orchida Grand Festival to close in the middle. Oh, there will be consequences.”
[End of example]
Just found this example from Contest Tie (by Encyclopika, of course). Here, Drew is told that his dad wants him involved with his business (which regards average pokemon trainers). He is basically told later in the story, he faces a choice: Become a trainer, and have no problems (which he doesn't want, as he hates his father), or stay a co-ordinator, and lose everything he competes for and loves.
Sympathy here is given because Drew is written as a likeable character. He's given a decision which will hurt his feelings, one way or another. You feel sorry, as he is against everything about his father (hint: past experience with his father and brother). I can't describe too much of it without spoiling it all (probably have already!) Also, May later is told this, which makes you feel symptahy for her too...
Anyways, a shoddy example from me, but hey, I tried. I'd just look at decent examples where people feel sympathy for a character, and look at it in detail. What makes you sympathise? How do they write that into the story? How is the atmosphere described? and other such questions.
(Credits to Encyclopika for the excerpt, so don't sue me please...)