Here are some more tips.
1) You are on the right track building out your category pages as that is part of how you want to silo your site. Keep it closer to 1K and not close to 400 words though. The more decent content with LSI KWs the better.
2) Interlink the products in those categories. If you have a category called golf shirts and are selling mens shirts, women's shirts, fancy golf shirts etc, interlink those product with one another.
3) Use long tailed KWs on your product pages also. If you have a man's golf shirt that has stripes, add in yellow golf shirt with blue stripes and use the <strong> tag on it. People search for specific things online often and you can take advantage of that by not only ranking for golf shirts but specific looking ones.
4) Keep searching out products and keep adding them and be sure to make the description on the longer end as opposed to a paragraph. Content matters a lot when it comes to Google liking your site.
5) Images - I'm not sure I shared this on this thread but Image SEO matters. I've shared my thoughts here on that -
http://ypick.me/using-image-seo-to-rank-a-web-site/
6) Backlink to your category pages, your product pages and your images once they are optimized.