I was really lucky the last time I was updating and sending out my resume. A friend of mine had just been laid off (not so lucky for her) and part of her lay off package was a course on resume writing and interviewing. She paid attention and found another job quite quickly.
She gave me her resume electronically and I just followed everything she did - there were 2 or 3 styles with instructions on which style of job got which style of resume. It must have worked for me, too, because I got several interviews when I used them, as well as getting a couple of different jobs. I won't need them again, I don't think. My job is reasonably stable and I don't intend to leave it until I retire in 10 years, come August.
Somebody upthread mentioned construction workers, applying for jobs. I wouldn't expect them to be in shirts and ties but I would expect them to be clean and neat, in well mended clothes. So knocking the dirt off their steeltoes, clean jeans or work pants with no holes in the knees or the back end, clean t-shirt, preferably collared, no ball cap.
I work in a job with a field element to it but most of the time, I'm in a laid back, casual office. Jeans and tees are pretty much the regular uniform. When my boss does interviews, he'll upgrade to slacks, button down or plain dress shirt, with a tie. Somebody coming to an interview here in a three piece suit would be considered to be trying too hard but if they interviewed well and had a good resume, that wouldn't knock them out of the running. Our AA is the one who books interviews and greets the applicants when they arrive, settling them in the lobby with some reading material if they are a bit early or the previous interview is running a bit over. The boss and whoever else is interviewing always ask her for her impressions at the end of the day. Anyone who is rude to her? Off the list. Frankly, she's the most important person to keep happy in this office. She does so much for us that the AAs in other offices across the province don't do and it makes our lives so much easier. She prefers it because she can keep a tighter rein on the filling and make sure stuff doesn't get messed up and that she can find it when she needs it.