Government contracting consultant Mark Amtower does not pull his punches when he describes LinkedIn profile images that fail to make a good first impression.

His verdict on a photo of a business woman wearing a colorful dress, standing on a beach: “Not professional.”

On a photo of a man in a business suit, who is seated, hugging several grandchildren: “Not professional.”

Third, on an image of a large boat. “Not professional, and all your clients will be thinking about is how you need to make more money to pay for your boat,” he said.

Amtower, a self-described “LinkedIn Black Belt,” teaches classes to government contractors who want to improve their LinkedIn visibility, credibility and connections. In five years, he has built his LinkedIn network from 150 connections to nearly 5,000. He runs several LinkedIn groups, including Government Market Master, and is a member of dozens.

The LinkedIn profile is the “honeypot” for attracting new clients and partners, Amtower says. “Done well, it will attract the right audience. Keep fine tuning and never let it be stagnant.”

He strongly recommends that you pay close attention to the facial expression in your photo: “Neutral is OK. A smiling face is better, and frowning is bad.”

Ideally, your photo should be shot by a professional photographer with controlled lighting.

A head shot, wearing business attire, is best. Showing your dog, your car or your hobbies is bad. Family photos and casual outdoor photos are “fine for Facebook, but absolutely not OK for LinkedIn,” Amtower says. A more subtle turnoff to potential contacts is having no profile photo, he added.

Here are more of his tips to improve your LinkedIn presence:

Use your name, and nothing but your name, in the top line.

Write a short headline under your name summarizing what specialized expertise or service you offer. This is where you can include certifications, specialty areas, and job titles.

Write a summary in the first person explaining how you can help others, and what you look for in return, and indicating with whom you want to connect on LinkedIn. Use Search Engine Optimization terms. Write in short paragraphs.

Give recommendations in order to get recommendations.

Consider linking with members connected to your connections, members in pertinent groups, members viewing your profile and people giving you business cards at events.

Write a personal message when inviting a LinkedIn member to connect; explain who you are and why you want to connect.