1. Start your document, blog post, LinkedIn profile, Google profile etc. in Word or a like application. Check your Document Review settings - make sure you do not have options set to ignore words in Caps or other terms. Spell- and Grammar-check.
2. Do not automatically accept word processor suggestions: Somewhere, out there today, is a major proposal that has the word "seamy" where "seamlessly" should have been. Really changed the meaning of the paragraph.
3. Copy your text into Notepad to strip underlying formatting & HTML that may create issues if you are pasting into a CMS.
4. Copy and paste using a Browser that has a spell-check option.
5. Used web-based resources if you are in doubt of spelling or meaning of a word. http://www.wordcentral.com/ from Miriam-Webster is a good, free tool. There are many others.
6. Have an objective party review whenever possible, or set the work aside for at least a couple of hours so you may review it with "fresh" eyes.
7. Hire the great folks at RescueResumes and be done with it!