"Find broken pages on your site which have inbound links with Webmaster Tools"
This is a very easy, and very often overlooked way of clawing back some of those hard earned back links. Get logged into Google Webmaster Tools and check the "Crawl errors" section. Then drill down to the "not found" results and next to each one Google will tell you how many links are pointing to that page. 301 the 404ing pages to a current page on your site to pass the link juice.
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Previous SEO Tips:
SEO Tip #33: Optimise with E-Commerce data
SEO Tip #32: Grab links to broken sites
SEO Tip #31: E-commerce with content
SEO Tip #30: Avoid canonicalisation problems
SEO Tip #29: Finding the right social networks
SEO Tip #28: Optimise after posting
SEO Tip #27: Live in your network
SEO Tip #26: Don't sacrifice user experience
SEO Tip #25: Integrate news sources
SEO Tip #24: Collaborate and track SEO actions
SEO Tip #23: Build personal relationships
SEO Tip #22: Don't be lazy during build
SEO Tip #21: Use old URLs for new content
SEO Tip #20: Use an existing domain
SEO Tip #19: Optimise internal links
SEO Tip #18: Rewrite offline press releases
SEO Tip #17: Create rewarding campaigns
SEO Tip #16: Information Architecture
SEO Tip #15: Check logs for longtail searches
SEO Tip #14: Use full-text date formats
SEO Tip #13: Don't be a link scrooge!
SEO Tip #12: Use Google Local Business Listing
SEO Tip #11: Write your own product descriptions
SEO Tip #10: Competitor Link Research
SEO Tip #9: Good usability means good SEO
SEO Tip #8: SEO Success = ROI not rankings
SEO Tip #7: Localise, don't just translate
SEO Tip #6: Get the on-page basics right
SEO Tip #5: Check the use before date
SEO Tip #4: Integrate SEO and PPC Campaigns
SEO Tip #3: Using Twitter
SEO Tip #2: Create Unique Content
SEO Tip #1: Stop! Keyword Research
Post by Further search marketing.