I'm not going to pretend that I always have the best grammar. I'm still not sure when to use "lay" vs. "lie". I occasionally have to look up when to use "effect" vs. "affect" even though when I write them like that it seems totally obvious. I've also been known to avoid using "i.e." and "e.g." because I'll almost always choose "i.e." regardless of which one should be used.
That being said, I think I have better grammar than the average schmo. I know when to use "your" vs. "you're" and "there" vs. "their" vs. "they're". I know, you're impressed.
In my lie lay effect affect i.e. e.g. confusion moments, I let Grammar Girl do the work. She's retro, smart, and willing to talk about participles.