10 Ways to Increase Your Site Crawl Rate

Update your content often and regularly
Make sure your server works correctly: mind the uptime and Google Webmaster tools reports of the unreached pages. Two tools I can recommend here are Pingdom and Mon.itor.us.
Mind your page load time: note that the crawl works on a budget – if it spends too much time crawling your huge images or PDFs, there will be no time left to visit your other pages.
Check the site internal link structure: make sure there is no duplicate content returned via different URLs: again, the more time the crawler spends figuring your duplicate content, the fewer useful and unique pages it will manage to visit.
Get more back links from regularly crawled sites.
Adjust the crawl speed via Google Webmaster tools.
Add a sitemap (though it’s up for a debate whether the sitemap can help with crawling and indexing issues, many webmasters report they have seen increased crawl rate after adding it).
Make sure your server returns the correct header response.
Make sure you have unique title and meta tags for each of your pages.
Monitor Google crawl rate for your site and see what works and what not

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