Implement obstacle avoidance methods and local navigation (move_base)

Hello, I would like to implement obstacle avoidance methods in Turtlebot2 (Velocity obstacles, VFH+. APF,...). And I do not know if I have to use pluginlib and do as D. Lu did. That is, implement the interface named nav_core::BaseLocalPlanner and do planning in computeVelocityCommands method [1]. Or maybe, it requires to do something else such as modifying costmap_2d [2], add PoseStamped ? So, does somebody may advise me on what should I do first, since I am a beginner using ROS ? [1] https://github.com/DLu/simple_local_planner [2] http://wiki.ros.org/costmap_2d