I recently read about a great exercise for growing your network. (This comes from the fantastic book "Book Yourself Solid" by Michael Port.)
Make a list of 20 people in the music business that you don't know personally but would like to know. Think in terms of impact. Who can most help you to achieve your goals in the business.
(Note: The most successful networking is done between two people who can help each other, not just a one-way street. That's a topic for another day but very important to mention!)
Next, try to figure out proactive ways to introduce yourself to the people on your list. Maybe you will be attending the same conference. Maybe they are passing through town with a touring orchestra. Maybe they are good friends with your current or former teacher.
Figure out some kind of commonality with the first person on your list and plan your first step towards connecting with them. Always think about whether your route to connect with them will be convenient for them. This is very important.
As anyone who has ever seen me present or perform knows, I am always happy to speak with anyone afterwards. But there have been plenty of times when I had another engagement (particularly at a conference) and only had 10 minutes to speak with the eight people who wanted to introduce themselves.
Maybe send someone an email ahead of time explaining who you are and get creative about how you might introduce yourself. If we are in the music business, we are creative people by definition! (Or we shouldn't be in the business!) Use this creativity for things like networking and not just how you finish a phrase.
This is a topic that could be covered in detail over 20 different blog posts. This is just one small idea of how you can proactively attempt to grow your network.
While you have to have the skills to back everything up (or everything else is moot!), the music business really is all about who you know. So do something about it!