Hunting for a job is even harder than doing the job itself, especially in today's economic climate. I believe first impression is absolutely crucial. First impression you want to project yourself obviously means your first contact with your potential employer. I know of idiots who thought they are dealing with a mate, and used words like "mate" to address the potential employer

I suggest "Mr", "Miss" are a good start. Politeness never goes out of fashion. Sprinkle your conversation with "please, thank you very much". Start with a "Good morning / Good afternoon" etc never hurts.
Most important of it all is your spelling ! Yes, get you text checked and checked again. Use a spell checker. A friend of mine who runs an recruitment agency told me that out of the applications in the hundreds, or even thousands, it is near impossible to wade through them all. So any sign of careless spelling, it is out
Personally, I am not sure of people who carry their hardware store with them. I am talking about all those piecing and crap. And ridiculous tattoos, no way.