Good Morning, All:
I find that I get more involvement and roleplay in my games, in part due to my use of what I call "End Of Session" points.
At the end of each session, we take ten minutes or so to hand out a variety of points for certain things. Each person gets one vote, and it could be for themselves or another person, in each category. With a person gets two or more votes, they earn a point for that category. Each point is worth (10 x highest character level) XP, or 1% of what the highest level character needs to advance. It's small but makes a difference over the length of a campaign.
My "End Of Session" categories are simple:
* Learning Curve - List three things you learned about the campaign world this session. You cannot repeat anything anyone else has listed previously. This encourages players to pay attention to the game world and interact with NPCs. (I run games rich in backstory and world secrets, so this helps keep attention focused on them.)
* Alignment/Allegiance - List one solid example of an action your character did this session that supported your alignment/allegiance. This encourages the players to consider their character's alignment and try to act accordingly, keeping the focus on the character.
* Roleplay - Pick the person that made the game the most fun for you this evening, by whatever criteria you choose (in-character acting, best one-liner, whatever works for you), and tell us why. It encourages players to view the game as a form of entertainment, and hopefully allows them to work towards the group's enjoyment. It's also good feedback to hear that people like how you play your character, and hopefully re-inforces good practices.
* Heroism - Pick the person that put their characters at risk the most so that others might succeed. This encourages cinematic action and daring deeds, which in turn increases all of our enjoyment at the table.
I've found that these simple reminders work to encourage well-rounded play. The rewards are small but tangible, and over time, the better players will shine through their higher XP totals. These four categories are the areas of the game I want to reward, but you can do other categories if you so choose. Feel free to use this method in your own games, if you think it might help. It did for me.
Hope This Helps,
Flynn