Keywords in top 5 position?

Hello Friends,
I have been working on one of the SEO project from past few months and by working consistently on this I had achieved my first target that is to bring all the keywords on top ten position but now I am focusing to bring these in top 5 position and some of the techniques which I am using are directory submission, social bookmarking, forum posting, blogging, article submission etc., Still by using all these techniques the keywords are not yet stable on their position for example one of the keyword was on position 4 and now it has dropped down to position 7. Please suggest some techniques which can be helpful to bring all the keywords in top 5 positions and make them stable.
Thanks.