Here is some advice on how to avoid some mistakes, some simple ways to check your spelling and Shakespeare's birthplace.
First of all there's the spellchecker in Word (you'll have to change the settings in Word to British or American English- go to "verktyg/ språk/ ange språk"). Do not underestimate this tool - it may make mistakes and miss things but some things it will spot. The interesting thing is that you'll notice some mistakes and you'll have to think while using it and ignore suggestions that are outrageous. Not all mistakes are spotted so you can't rely on it completely. Nevertheless use it!
Secondly, there's Atomica (my personal favourite), a great help for those of us who can't remember what year Shakespeare died or what "ubiquitous" means. This is a tool that you download from www.atomica.com (it was free when I made this course) and once it's activated and you're on line you just have to "alt-click" and point your cursor to a word and you'll get an explanation from a dictionary, more links, or a web search etc. If it's a person you'll get quotes, biographies etc. It's magnificent! OK - it makes mistakes too and strange choices sometimes, but it's still an excellent quick help.
Thirdly, there's the net. The net is full of information, there are tips on writing and templates to be found.
The point here is:
Use whatever help you can get while reading and writing (using the spellchecker or asking a friend to check what you've written is not cheating) as long as you think and learn while you're doing it. What kind of mistakes do you tend to make - and why? How can you avoid them?
An even more important point is:
Don't focus too much on possible mistakes, think about what you want to say instead!