Post on different sections of the forum. Don't limit yourself to one board.

Try not to post on megathreads that have no point in discussing the topic any further because it's already answered countless times.

Here are some topics that might help you in getting a merit or two.

Guide for getting + merit
Newbie's Guide to getting merit
TMAN's guide to getting merit
Motivation thread for users that can't get merit because they aren't good in english