How to optimize Broad Match Keyword for Quality & Relevant Traffic to Improve ROI

Broad Match option is popular used keyword match type in Adwords for larger  number of search targeting. For Example i have Adgroup shoes. Some of our broad match keywords are:

buy shoes
shoes for men
women shoes
shoes
nike shoes
Adidas shoes
reebok shoes
shoe online
footwear

So i have putted all relevant keyword into Adgroup and expecting that we would get good visitor to our site. Our object is to sell shoes through this Adgroup.

I was getting very less conversion for this Adgroup and cost was higher. I would like to describe you what i did to control irrelevant traffic which was causing less conversion and benefit. Read below some of the steps i have taken to over come this issue:

Downloaded keyword from Shoes Adgroup
Downloaded Search Terms One By One Keyword

Started finding that which search term is less conversion type
Excluded that search terms from it. For Example Broad Keyword Shoes, i was getting search terms like Shoes manufacturer, shoe maker, shoe designer etc.

So i excluded those keywords.

I also find out that which keyword is less conversion type to exclude them
If i get some fixed search term in Adgroup then i putted in negative list.

For More Reference: http://www.wordstream.com/expanded-broad-match
http://www.wordstream.com/broad-match