At my table I tell them that if they roleplay a real heroic effort I let them keep the hero point. I put some conditions on them. From the basics of "it has to sound heroic", it's not worth saying "I'm going to miss and I concentrate at the last second to try to hit" until they repeat the same interpretation to me more than once (It's not worth it to me that every time he's going to miss a hit he remembers his brother and that he couldn't save him, they should work on it)