You can start by taking a look at the CarrotPlanner local planner, it is one of the most simple and you can build from there.
To specify a planner different from the default ones, you can add one of these lines to a launch file, where you launch the move_base node.
## alternative global planners ##
<!-- <param name="base_global_planner" value="goal_passer/GoalPasser"/> -->
<!-- <param name="base_global_planner" value="carrot_planner/CarrotPlanner"/> -->
<!-- <param name="base_global_planner" value="SBPLLatticePlanner"/>-->
## alternative local planners ##
<!-- <param name="base_local_planner" value="pose_follower/PoseFollower"/> -->
<!-- <param name="base_local_planner" value="dwa_local_planner/DWAPlannerROS"/> -->
<!-- <param name="base_local_planner" value="eband_local_planner/EBandPlannerROS"/> -->
For example:
<node pkg="move_base" type="move_base" respawn="false" name="move_base" output="screen">
<param name="base_global_planner" value="goal_passer/GoalPasser"/>
<param name="controller_frequency" value="10.0" />
</node>