When I go to post something I do my best to keep it correct in regard to spelling and gramar. I will not obsess over it, but I will glance over it and see if there is anything that really stands out. Usually I would correct something before posting, but I often will find a word that doesn't make sense, or a mistake later on if I am still looking at other posts in the forum. I will try to do my best. I will look up a word if I am unsure of its spelling, or I will read something out loud to myself to make sure that it sounds alright.
I would fall under the catagory of using edit often. I do correct mistakes when I notice them because I want what I post to look nice. I want people to notice what I write and understand what I write rather than try and figure out what I meant to type. Still, I really only edit small mistakes - perhaps a word here or there. I do not make big changes like add a new paragraph, or remove an entire paragraph. I just like to do touch ups, which is why I really like the edit button. The edit button allows the poster to do touch-ups when they do not notice something at first, or when they want to change a phrase to make something sound better.