As much as you might like to add every single person you know on LinkedIn, or strike a conversation with any random guy at an event, these actions aren't really very useful. If you want to create valuable connections, don't do the following things.
DON'T ADD ALL THE PEOPLE
Look, you don't have to add everyone from your university on LinkedIn. You don't have to add all your relatives either. Only add people who are relevant to your work, those who can help you out somewhere down the line.
DON'T SCHMOOZE TOO MUCH
Some people don't enjoy it when you kiss up to them. If you can't hold a practical, substantial conversation, then it's best to not talk at all.
DON'T FAKE IT
Listen to the Disney movies for once and be yourself. Don't try to portray yourself as someone that you're not, and don't claim to have skills or experience that you don't really possess.
DON'T EXPECT IMMEDIATE RESULTS
Don't reinforce the stereotype that millennials want instant gratification. It takes time to reap the benefits of networking, so be patient. You never know when one of those contacts you made years ago will come in useful.