This post is for all new comers ! You should reply to those topics which have less replies because less replies means your comment must be read by the writer(which is posting that topic) you can check that which post have less replies by simply taping on option below the "create new topics" the option will be "sort by(date)" click on the Date option and the topics will be there do mention author in your comment in sha Allah you will get good reputation by doing this,must try it.
Give me heart if you like it.