Even in an improving job market, competition for top positions has, in many cases, not lessened. There are more jobs overall, but maybe not more of the kind you want.
That means if you want to get hired, you have to make sure you do everything possible to put yourself in the right position. Doing that starts from before the interview, and it continues until your first day of work.
Getting hired has become a long process where a small mistake early or late in the game can sink you. That may sound depressing, but it's an easy enough problem to solve if you take a measured approach to each step in the process. That won't get you every job, but it may provide the small edge you need.
Have your resume professionally done
When my now-13-year-old son was born, I worked in my family's business for four years. For the next roughly four years after that, I had jobs where either a resume was not needed or was not too carefully scrutinized.
Because of the gap in time where I did not need a functional resume, I had no idea the basic format of mine had become out of date. As I was applying for jobs I was well-qualified for, I eventually realized something was wrong.
To correct it, I used a paid service to modernize my resume. Once I did that, the interviews started flowing. And while the cost was substantial based on my life situation at the time (about $400), it was well worth it once I started landing interviews.
Have more than one cover letter
Some jobs may not even require a cover letter, but for the ones that do, it's very important you customize yours for each job you apply for. Use your cover letter to address things in the job ad where your ability to perform the job may not be obvious from your resume.
Your cover letter should also show enthusiasm and a bit of your personality. Don't be goofy or too personal, but write in your own voice. Address some specific requirements named in the job listing, telling the person doing the hiring how you would handle them.
Hire a copy editor
Even if you are a decent writer, it's always a good idea to have a professional editor go over your materials. This need not be an expensive proposition, as these are not long documents, but mistakes on resumes or cover letters stand out.
Word-processing software can help, but it won't tell you that writing "utilize my abilities" instead of "use my abilities" makes you seem a bit pretentious. Copy editors can turn bad to good and good to great. Or to put it another way, a copy editor is the difference between expressing your admiration for Usain Bolt, the famous sprinter, and Yusane Blot, who is probably not a person.
Do your homework
While a job interview will probably be mostly about you, it's important to know as much as you can about the company, the position, and and well-known, public facts about the interviewer. (Congratulating him or her on an industry award is great, but complimenting what he or she had for dinner last night is creepy.)
You will also want to do your homework when it comes to your interview skills. If it's not something you're great at, practice.
Have the right clothes
When you interview it's important to look the part. In nearly every case that means wearing a suit for a man and the equivalent for a woman. You will also want to cover up any tattoos and remove any non-earring piercings.
In general, unless otherwise told by the person interviewing you, those clothes are a standard requirement for interviews. That's the case even if the job does not require dress clothes. It's always better to be a little too dressed up for an interview than a little too casual.
Bring your materials
During your interview, the person conducting the meeting may or may not have copies of your resume on hand. You'll want to make sure you do in case the need arises for someone on the other side of the table to refer to it.
In addition, while you may not need it, you should also have multiple copies of your references on hand. If you do, than you will be ready if asked (and cut some time between interview and offer if things go well).
Send a thank-you note
On the same day as you interview, or first thing the next morning, send a thank-you note. Email is fine, if that's how you've been communicating, but a handwritten card is a nice touch.
This is sort of a cherry-on-the-sundae move. It's a final chance to move the needle toward you in a subtle way. That could be important if you and another candidate are being debated.