Something people ask me about all the time these days is how to get paid off with their big hands. Sometimes they can't even get calls when they value bet hands like top pair or middle pair either!
One of the main reasons for this is playing too tight. As the famous saying goes, "you have to give action to get action." You can't sit around waiting for the nuts all day and expect people to be lining up to pay you off.
But secondly, a lot of the time the issue is simply the bet sizing itself.