User-Agent: *
Crawl-Delay: 30

Disallow: /*?
Disallow: /index.php/
Disallow: /catalog/product_compare/
Disallow: /catalog/category/view/
Disallow: /catalog/product/view/
Disallow: /wishlist/
Disallow: /admin/
Disallow: /catalogsearch/
Disallow: /checkout/
Disallow: /onestepcheckout/
Disallow: /customer/
Disallow: /review/product/
Disallow: /sendfriend/
Disallow: /enable-cookies/
Disallow: /LICENSE.txt
Disallow: /LICENSE.html
Disallow: /skin/
Disallow: /js/
Disallow: /directory/

#Lets consider each groups of commands separately.
#Stop crawling user account and checkout pages by search engine robot:
Disallow: /checkout/
Disallow: /onestepcheckout/
Disallow: /customer/
Disallow: /customer/account/
Disallow: /customer/account/login/

#Blocking native catalog and search pages:
Disallow: /catalogsearch/
Disallow: /catalog/product_compare/
Disallow: /catalog/category/view/
Disallow: /catalog/product/view/

#Sometimes Webmasters block pages with filters..
Disallow: /*?dir*
Disallow: /*?dir=desc
Disallow: /*?dir=asc
Disallow: /*?limit=all
Disallow: /*?mode*
Disallow: /catalogsearch/
Disallow: /search/
Disallow: /customer/account/login/
Disallow: /*?SID=
Disallow: /*?PHPSESSID=
Disallow: /*?price=
Disallow: /*&price=
Disallow: /*?color=
Disallow: /*&color=
Disallow: /*?material=
Disallow: /*&material=
Disallow: /*?size=
Disallow: /*&size=

#More reasonable to use canonical tag on these pages.
#Blocking CMS directories.
Disallow: /app/
Disallow: /bin/
Disallow: /dev/
Disallow: /lib/
Disallow: /phpserver/
Disallow: /pub/

#Commercial Crawlers
User-agent: BLEXBot
Disallow: /
User-agent: MJ12bot
Disallow: /
User-agent: TwengaBot
Disallow: /
User-agent: AhrefsBot
Disallow: /
User-agent: WotBox
Disallow: /
User-agent: Baiduspider
Disallow: /
User-agent: Yandex
Disallow: /
User-agent: YandexBot
Disallow: /
User-agent: MegaIndex.ru
Disallow: /

# Allow Google
User-agent: Googlebot
Disallow:
User-agent: Googlebot-image
Disallow:
User-agent: AdsBot-Google
Disallow: