Point 1: LinkedIn is not Facebook for business. It is about networks of people you know. Don’t send me a connection request because one of your friends knows me unless you are prepared for Point 2.
Point 2: If I don’t know you, make it clear in your invitation why we should connect. LinkedIn makes it too easy to send generic “I’d like to add you to my professional network” requests, but those are just brainless. When you don't customize your request-to-connect text, it is a dead giveaway that you don’t understand how LinkedIn and networks work.
Here is a link on writing a good LinkedIn connection request
Here is a link to more perspective on connecting in general
Point 3: Make sure your profile includes a professional-looking photo of you. This means no pictures with pets, selfies in front of your computer’s monitor, standing at attention in front of a wall, or with your significant other. Use an image you would put on a business card. Not having a picture makes it look like you have either have something to hide or are paranoid in which case you shouldn’t be on LinkedIn. The lack of a picture is a show stopper for me connecting with you unless I know you really well and then you will get a comment from me.
Point 4: Fill out your profile as completely as possible. I am going to look at it before I connect with you. Focus on things you accomplished, not what you were responsible for.
Point 5: Create a standard update that is more than three sentences long to tell me how you are doing and the projects you are working on. You can use this if I accept your invitation. I keep one at the ready and include it with all my connection acceptance notes so it only takes me a few minutes to send. I also customize the subject of my reply to a connection request, which will come as no surprise to anyone that has been reading this blog for a while or knows me well. I regularly adjust my personal update so it is current.