1. Join A Book Club.
This is where I met the most wonderful reader friends in my life. I recommend looking for a local book club in your city or town. Most indie bookstores and libraries host their very own. Visit their websites or call them to find out more details. Don't give up. If you join a book club and it doesn't mesh well then try a different one. A good book club will have recent reads and maybe even age ranges. Join the group that works for you and don't be afraid to ask questions. I would only recommend starting your own book club if you have an extroverted personality. The book club admin must be organized and must be able to lead the conversation. They have to be able to fill those silent moments. Below are some links to sites to join book club or to start your own.
Also do a google search with your city & book club to see what pops up. Facebook is another place to look. Just make sure its a book club that meets in person. Please be safe. Make sure to tell someone where you are going and trust your gut.
Now this one might be trickier than joining a book club. This also involves starting conversations with strangers. Here's the thing, you are already going to an author event and love to read, the other people there like the same thing. SCORE! Most author events have a facebook group or a facebook event. I would recommend you to post and join conversations. I would even recommend posting that you would like to have a buddy join you. Lots of people do not like going to events alone so there is 50/50 chance you might get a response and have someone join. Also you can sign up to be a volunteer and meet reader friends that way. If all else fails then become friends with authors. Trust me, they work in a lonely profession and would like to have friends too.
I understand not everybody can physically make friends either due to personal reasons or location. Social media is the answer. I feel its better than nothing and honestly I have met some great people online. Even though I haven't met them in person I know I can count on them as friends. Lots of authors have Facebook groups and this way you can meet folks who love the same kinda books you do. If your favorite author doesn't have one then ask if you can start one for them. Then there is also Goodreads (the social media for all readers) has quite a few groups to join. I would recommend there to look for online book clubs. I also have met quite a few YA fans on Tumblr. It seems if you reblog similar pictures you will find people with similar interests. Go figure. Anyways, below is a list of links to groups I've found to make online friends.
I really do hope this helps anyone looking for friends. If you have any recommendations or are also looking for friends then please let us know.