I think there is already much information you can have by those comments above, quality posts are only the key for receiving merits. There are many merit source in this forum and they will not hesitate to give merits for all those members who deserve it,

You may create a topic and create a comment both can trigger the merit as long as it is quality and helpful, entertainment could be in some ways.

You may also visit some profile with a good number of merits and see how they get those merits, check how they construct the message. Constructive posts make your content quality and the information and concept behind it. If you are not good at English then you may be active on your local boards which will make you more comfortable.