It’s not enough to just sign up for LinkedIn, you also have to use it properly. And there’s the rub — click around the professional social network, and you’ll notice a spectrum of what users call proper that perhaps they shouldn’t. Here are just 16 examples of things they, and you, could do incorrectly on LinkedIn:

1. Not including a profile image.
Having no profile photo conveys that you have something to hide, and you don’t want to leave a potential employer guessing what that may be. It’s also just lazy and creepy, so find a photo of yourself and slot it in the space. It takes two seconds.

2. Not including the right profile image.
OK, maybe it takes longer than two seconds. Make sure the photo you choose is recent and professional. It doesn’t have to be a glamour shot (remember those?) but you do have to comb your hair. It’s OK to show personality, but not so much pizzazz that you appear goofy.

3. Botching your professional headline.
You have 120 characters at the top of your profile to grab the attention of viewers and inform them of what makes you special professionally. “Teacher,” “therapist,” or “consultant,” won’t pass muster. Be specific and explain what value you add to your field and for a company.

4. Leaving the summary section blank.
LinkedIn’s summary section is the bridge between the professional headline and the sections for experience and skills. Think of it like an elevator pitch. It gives an overview of who you are, what you’ve done, and what you hope to achieve as a professional. Plus it should make the reader want to continue scrolling down your profile page. Bonus: You have up to 2,000 characters to tell this story.

5. Listing facts and figures only.
A Google search will tell a recruiter where you’ve worked, what you did, and for how long. Use LinkedIn to tell a story Google can’t. Explain your responsibilities. Highlight the projects you’ve worked on, and contextualize your skills.

6. Cutting and pasting in your resume.
This is your chance to break away from a resume’s constraints. On LinkedIn you can go into great detail on your experience and accomplishments, whereas with a resume you have only one or two pages. On LinkedIn you can upload visual work samples that you may only refer to on a resume. Plus you can update your profile to show in real time what you’re working on or have just completed.

7. Fudging your skills and accomplishments.
Lying about your qualifications is grounds for firing, and it doesn’t matter whether you directly told the lie with your lips or indirectly deceived someone with your resume and LinkedIn profile. Be sure that you’re giving an accurate assessment of your professional life.

8. Cold contacting and connecting.
You should have many LinkedIn connections, and it’s OK to connect with people you don’t know. But attempting to connect with those you neither know nor have any common ground with is awkward. Remember the website’s purpose, and form connections with people with whom something overlaps: like your profession, company, industry, or alma mater.

9. Using the default LinkedIn connection language.
The standard “I’d like to connect with you on LinkedIn” message has been around since the website launched, so it’s time to put it to rest. You don’t want to sound impersonal or seem lazy, particularly if you’re reaching out to someone you don’t know or don’t know well. Take a minute to tailor the request to the person who is receiving it and explain why you’d like to connect.

10. Not making your intentions known.
While on the subject of LinkedIn connections and messages, you should be transparent about who you are and what you want when you don’t know your new connection. For instance, if you’re planning to pitch business ideas, be upfront. If you’re a recruiter who likes to keep tabs on promising engineers in the Seattle area, state as much.

11. Neglecting your privacy and broadcasting settings.
Your profile should be public, but your activity doesn’t have to be. It could be annoying to your connections and embarrassing for you if every little profile update is broadcast, so go to Privacy & Settings to adjust what activity people can see. For stealth LinkedIn users, there’s also an option to remain anonymous when viewing other people’s profiles.

12. Being a bugaboo.
If someone denied your connection request, she won’t reconsider on the second and third attempt. Don’t clog up your connections’ timelines with excessive updates. Don’t use LinkedIn Groups just to self-promote. In other words, use common sense.

13. Recommending and/or endorsing everyone.
It’s easy to endorse connections for skills that they may or may not have, because LinkedIn asks if you’d like to. Reserve the endorsements and recommendations you dole out for those with whom you’re familiar. Keep in mind you can tweak your settings by selecting “Edit Profile” and then unchecking the box for “Show me suggestions to endorse my connections” in the Skills & Endorsements section.

14. Being stingy with recommendations and endorsements.
Don’t take the previous tip to mean you shouldn’t recommend or endorse anyone. The best LinkedIn connections are mutually beneficial, and it looks bad to other users if you’re always a taker and never a giver.

15. Using LinkedIn as you would other social networking sites.
Facebook, Twitter, Instagram, and Match all serve unique purposes, so use them as such. LinkedIn is primarily a business networking site, not a place to share your kid’s first steps, rant about social issues, or flirt.

16. Not using LinkedIn in the first place.
According to Jobvite’s 2014 Job Seeker Nation Study of 2,135 adults, 94 percent of recruiters are active on LinkedIn, but only 36 percent of job seekers are. Are you part of the majority or minority? If you have a professional services or corporate occupation, you especially need to have a profile where you avoid all the aforementioned mistakes.

Jada A. Graves is the Careers editor at U.S. News. You can follow her on Twitter @jadaagraves, circle her on Google+, or email her at[email protected].