2. No photo. Bad photo. Wrong photo
The web is an impersonal place. If you want to connect with people on an emotional level, you need to make it personal. Your headshot can help with this. But all headshots are not created equal. Make sure yours is on-brand and of high quality. Invest in a headshot taken by a professional. Don’t use a photo your mother took of you at last year’s family beach outing. Don’t use a selfie. And make sure you’re facing forward or to the left (looking into your content). When you’re looking off-screen, it sends a subtle message that you don’t believe your own content. Now that LinkedIn uses your photo to show how you’re connected to others and those you endorse, your headshot is visible well beyond your own profile.
2. Me-Too headline Don’t use your current job title as your headline (that’s the default, if you don’t customize it). If you do, you’re making yourself a commodity – interchangeable with anyone else who shares that job title. Instead, your headline needs to let people know what you do. It also needs to feature the keywords you want associated with your name. And it should entice people to read more about you. Use all 120 characters to solve these three goals simultaneously.

3. 3. Using LinkedIn as a resume LinkedIn is not a resume. Think of it as your personal web site. Your resume provides the chronological details of what you’ve done. Your LinkedIn profile tells the viewer who you are. Your summary is a bio – an interesting and compelling description of you, what you’re passionate about and how you deliver value to your clients and/or colleagues. Use all 2,000 characters, making the profile replete with all your keywords.
4. Only using words Now that you can embed images and videos into your profile, you have the opportunity to create a true 3D self-portrait. LinkedIn lets you build a portfolio, so use it that way. Create a video bio or thought-leadership videos to embed in your summary and experience. And incorporate white papers, images and other media to distinguish your profile from others. Use all the complimentary elements LinkedIn offers to tell a compelling story – your story.
5. Making it hard for people to learn more Fill in all the elements of the Contact Info section. Use the three web site links to showcase your YouTube videos, articles you have written, your company website, and other engaging samples. You can also make it easy for people to connect with you by including your email address, phone number, Twitter handle, etc. You’re competing against other dynamic LinkedIn profiles. Yours will get skipped if you make it tedious to connect with you or learn more about your talent.

4. CONTACTS LinkedIn is great as your portfolio, but its value doubles when you use it as a tool to build and maintain your professional network. Don’t let these common mistakes prevent you from growing and nurturing your network.
6. Using the default “I’d like to add you to…” connection request If you really want to create an impression, personalize all contact requests by indicating why you want to connect. If you use the generic message, the first impression you deliver is “I’m generic.” Here are some alternative ways to phrase that crucial introduction: “It was great meeting you at the AMA conference,” or “I see we both share an interest in …” or “I enjoy your posts and comments in the project management group.”
7. Having 499 or fewer contacts Having the magic 500+ contacts makes a psychological impact on those who view your profile. It can communicate that you’re a veteran in your field with many allies who trust your ability. Plus, your contacts may be valuable to others. The more contacts you have, the more value you can offer. Work hard to get to 500 by adding contacts from your past roles, linking all your email addresses and connecting with everyone you meet.

5. 8. Sending mass LinkedIn mail that starts with “Hello… ” Sending a generic email to a group of contacts will not only yield little or no response, it will annoy your contacts. If you want to reach out to your contacts, send them personalized messages or post to groups.
9. Not using tags LinkedIn can become your single contact management tool. Now that you can add tags to your contacts, you can organize them. Since you can easily add people from your various email accounts, you can create a single resource to manage all of your contacts. Remember to connect with every new person you meet. Then you can throw away their business card, reducing the clutter on your desk.
10. Leaving fingerprints When you’re checking out a new client, evaluating a business partner or looking to poach talent from a competitor, you may not want them to know you’re looking at their profiles. You need to do your sleuthing under the radar. To do that, change your privacy settings to become anonymous. Then change them back once you’ve completed your research.