One thing I've found particularly for German speakers is the use of phrases like "since 2 years". A native speaker would say "since 2 years ago", fixing the reference to a definite point in time rather than a duration alone.
I'd love a service that would fix such mistakes in my blog posts to make them look more native; something like an online mum that would fix the turn of phrase I use. I'm french, and this is typically the kind of mistakes I do all the time as well.
"...mistakes I _make_ all..." would be a more 'native' wording. (That isn't a dig, by the way, just given as a piece of information.)
My wife is Italian, and it's amazing how many constructs you come across that are correct, but sound odd. Defining rules for many of them in English is almost impossible given the unstructured nature of the language, which drives her mad given her background as a Mathematician.
It also annoys her no end that most people don't correct/question her if they understand the intent of what she said. They feel they'd come across as rude pedants, but she wants to know so that she can improve her grasp of the language.
While I don't want to go too far down the road of being your online mum (:P), I'd be happy to give your blog posts a once-over. Just email me your drafts (address in profile).