I’m not known for my etiquette. For instance, I often forget to send birthday cards to family members,; or I forget their birthdays entirely. When I’ve forgotten birthdays, I’ve essentially “dropped the ball.”

There are a number of ways jobseekers “drop the ball” in their search. They may not be aware of the mistakes they’re making, or they simply may not care. But it only takes dropping the ball once to lose out on an opportunity. Here are seven mistakes that come to mind.

1. Don’t update their résumés to reflect the job requirements. Some of my customers admit to sending a cookie cutter résumé, or one-fits-all, to a prospective employer because it’s the easy thing to do.

Not recommended. It’s sort of like giving someone a Valentine’s Day card that you’ve given your loved one the year before…and the year before that…and the year before that. In other words, you’re not showing any love.

Employers hate receiving résumés that aren’t written to them, ones that don’t address their needs and concerns. So make the extra effort when writing the most important document you’ll write until you land a job.

2. Don’t send a targeted cover letter. Again, like the résumé, the cover letter must reflect the skills and experience that are needed for the particular job. Your cover letter is a great way to tell your story and point the reader to the key accomplishments on your résumé.

One customer of mine sheepishly admitted that she once sent a cover letter with someone else’s name on it. That’s just plain embarrassing but goes to show you that care goes into writing and addressing the requirements of the job.

3. Fail to follow up after sending the documentation. Unless the employer strictly says, “No phone calls, please,” follow up to see if she has received your material. Employers aren’t dumb; they know why you’re calling. You’re calling to put a voice to the résumé and cover letter. In that case, make sure it’s a good voice.

Be prepared to talk about your interest in the job and company, but most importantly be prepared to state what makes you better than the hundreds of other applicants for the job. Have your personal commercial ready to deliver, a commercial that’s tailored to that particular job.

4. Avoid networking. Even though you’ve heard over and over again that networking is the most successful way to land a job, you would rather apply for jobs online. Guess what, the majority of jobseekers are applying for jobs online, and these jobs represent 20% of all jobs available in the job market.

The best way to land a job is to penetrate the Hidden Job Market by networking. Employers would prefer promoting their own employees, but if that isn’t possible, they’ll turn to referrals. The only way to be referred is by knowing someone at the company or knowing someone who knows someone at the company.

Networking doesn’t come easy to everyone, nor do some people like it; however, it must be done. You don’t necessarily have to attend networking groups, but you should make it part of your daily routine. Network wherever you go, whether it’s at a sporting event, your religious affiliation, your dentist’s office, a social gathering.

5. Aren’t taking LinkedIn seriously. I know this is tough for those qualified jobseekers who don’t know what LinkedIn is and don’t understand why it’s important in the job search. I see the dear-in-the-headlights look on my LinkedIn workshop attendees when I ask them how their profile matches up.

These are people who are curious about the application—how it can help in their job search. Well, it can’t help if your LI profile isn’t up to snuff. Rather it can hurt. Here are a few ways it can hurt: 1) it’s identical to your résumé in that it doesn’t provide any new information; 2) it isn’t fully developed; 3) you only have a few contacts or recommendations. There are many more mistakes you can make with your profile.

As a side note, the other night I was talking to a recruiter from RSA who said he spends every day on LinkedIn looking for people to fill his software engineer positions. One point of interest: he told me Monster.com is dead to him. This is how important LinkedIn has become.

6. Don’t prepare for the interview. At the very least you should research the job and the company so you can answer the difficult questions. Take it a step further by gathering insider information on the job and company. Some of my customers have been savvy enough to use LinkedIn to contact people in the company.

However, the night before you can’t locate your interview outfit. You haven’t taken a drive by the company to see where it’s located and how long it will take you to get there. How many times were you told to practice answering some of the predictable questions you may be asked? Again, can you answer questions like, “Why should I hire you” or “Can you tell me something about yourself”?

7. Don’t send a follow-up note. This one kills me. After all the hard work, you don’t follow through with a Thank-You note that shows your appreciation for being interviewed, mentions important topics that were discussed at the interview, or redeem yourself by elaborating on a question you failed to answer. I tell my workshop attendees that the interview isn’t over until they’ve sent the Thank You note.

Don’t drop the ball for any of the aforementioned reasons; instead keep focused on one of the most important times in your life. My not sending birthday cards to my relatives, or even forgetting them all together, is minor in comparison to losing out on an opportunity.