Check your impression share to make sure you aren’t losing out on impressions because of low bids. DSA is a very powerful tool when used correctly. I would create a dsa campaign that targets all of your website pages and from there fish out the ones that are performing well. Separate them into campaigns/adgroups to adjust bids accordingly. Make sure to look at your search terms every two months or so to see if you are picking up traffic from irrelevant keywords and add them as negative keywords to trim the fat off of the campaign