Article submission is a great way to get links with niche keyword and traffic to your site. Some important tips I usually follow are: (1) Submit one article to not more than 50 directories. Submit other article to other around 50 article directory. (2) Once filter your article directories with nofollow tags and don't allow any link. i.e. there re 100s of article directories present than there is no need of submitting article to such directories which are no follow or not allow any self link in author bio section. (3) Complete 1 article submission to all decided directories in one day only. (4) Check out submission guidelines once becoz many directories allow self link in body also, some allow 2 links and some allow three links. Note down this information about allowed links in your .xls sheet of list of article directories for all directories. (5) Be very careful while writing author bio. You should place 2/3 links there but it should not be like sealing purpose or pure advertising. (6) use roboform to make submission faster. (7) make your article very informative without any grimmer mistakes, use simple English with a very attractive title. Hope this will help you. Good Luck.