It seems that to err is human, so here are some tips that I came across that are said to help improve the accuracy of written communications. Please note that I used the word accuracy. It is really tough to produce 100% error free work without a full time editorial staff. So with that said, cut yourself some slack and try these methods

1. Step away and come back to it (Give yourself time)

2. Read aloud

3. Print it

4. Read your work backwards. Read the last paragraph first and work your way to the beginning.

5. Use a tool like:

a. Grammarly ($139.95 a year)
b. Grammar Girl
c. Merriam-webster
d. Purdue online writing lab

6. Type slower (my tip) – strive for accuracy in your typing. Take this typing test to see how fast and accurate you are. http://www.careerstep.com/free-typing-test
7. Use a thesaurus to ensure you select the proper and precise words for your communications

Articles/Resources
http://classroom-aid.com/2011/09/30/3-secrets-for-better-error-free-writing/
http://www.quickanddirtytips.com/education/grammar/proofreading-tips
http://www.everydayfamily.com/blog/4-helpful-sites-to-keep-your-writing-fresh-and-error-free/