1. Every artist has a mailing list. Join it! - This is the best way to ensure that you always know when someone is going on tour. If you are interested in going to see someone and they have just put out an album, go to their website, and get on that list. They will send you the entire list of their tour dates when they are announced which gives you the chance to choose the best show for you. Sometimes, it might be worth it to drive a little farther for a weekend show. Also, a ton of artists these days are offering exclusive ticket presales to members of their mailing list. The majority of the tickets I have bought in the last year have been during these presales. That includes Ed Sheeran, One Direction, and Justin Timberlake. It's a great way for the acts to cut down on scalpers which they have all been working really hard to do. You might also want to consider joining their "fan club" if they have one. A lot of them cost money per year to join, so I don't really do that. The one fan club I'm in is Taylor Swift's. It was totally free to join, and it got me the chance to buy pit tickets to her Red Tour.
2. Follow their social media sites particularly Facebook and Twitter.  - If you are anti filling up your email with the artists emails, you need to at least like them on Facebook or follow them on Twitter. These are the places that they start to drop hints about touring, and make the announcements first. Social Media is the best way to know an artist is going on tour the minute they announce it.
3. Make a Ticketmaster account. - We get emails from Ticketmaster and LiveNation all the time. These websites ask you to choose a city that you like to go to events in. On Ticketmaster, ours is Nashville or Birmingham, and LiveNation is Atlanta. These sites send out emails when new events in those areas are announced which makes them another great way to stay on top of tours. They also can easily store your tickets online for upcoming events and remind you when they are approaching.
4. Know the ticket prices beforehand. - When you go to purchase tickets, Ticketmaster gives you 3 or 4 minutes to decide if you want the seats they found for you. This is not the time to decide if you are willing to splash out $90 on a seat. You need to know what you are getting into beforehand, or you are going to freak out when the clock is ticking. That could lead to giving up tickets and regretting it later, or thinking you can afford something when you can't.
5. Know exactly how many tickets you are going to buy. - When you are talking about the amount of money and planning that goes into a show, you really can't have your friends backing out on you. You have to know exactly how many seats you want. Most of the time, I just go for two tickets. I know that one of my parents will come with me if all else fails. I definitely start talking to my friends about events as soon as they have been announced to see how they would feel about going to them. Concerts are more fun when you are with people who like the artist as much as you do. Another thing about ticket amount, the more tickets you set out to buy the more likely it is that your tickets will not be good. It is harder to find 6 seats together than it is to find 2. Be sure that you are willing to sacrifice good seats to go in a big group because it could happen.
6. Take a look at the seating chart before the tickets are on sale. - When the seat options are presented to you, you need to know where they are in the venue. Most venues are pretty straight forward, but I've seen some things that are really confusing to figure out in those 3-4 minutes you are given. Have a general idea of where you want to sit. If you just want to be in the room, that's great. You will have tons of options. If you want a "good" seat, you need to take some time to decide what "good" is to you. Personally, I will never buy a ticket in the top level of an arena. I've been too close at shows for that to feel worth the money to me. Going into a ticket sale, you need to know where you want to be and how to read a seat map.
7. Recruit friends to help you. - Ticket buying is better with friends. The best kind of situation is always one where you have multiple people logged on trying to get tickets. You'll be able to compare seats, and choose the ones that suit your taste.
8. If you want good tickets, be online a few minutes before the they go on sale. - Most tickets go on sale at 10 AM local time on random days of the week. Be aware of the "local time" part if you are buying a show for a different city, and do your timezone math. You want to be on 5 or 10 minutes before that to give you time to log in, and be ready with any codes you need if you are trying a presale. I normally start refreshing the page 2 minutes before they go on sale, and the sale opens when it opens. 
9. Check StubHub and other resale sites. - If you happened to not get tickets when they went on sale, start checking StubHub and other sites like it. You can set price alerts for certain sections in a venue, so you'll know if anything you would be interested in buying gets listed in your price range. A lot of the tickets on these websites are very overpriced because they are full of scalpers, but you can get lucky with people who just want to unload their tickets because they can't go to the show.
10. Wait it out. - If you aren't absolutely desperate to go to the show, then I suggest waiting it out until closer to the show. StubHub prices will drop closer to the show when people just want to get rid of their tickets. Also as the venue starts to set up for the show, they will often have extra seats to sell. Back in 2010, I got tickets to see Justin Bieber (forgive me please, but we are talking swooshy hair phase people) 4 hours before his show. The seats were in the first side section right by the stage, and they were amazing. I got my Taylor Swift pit tickets 2 weeks before. If you are interested in going to a show, start checking a couple days before to see if anything opens up.
11. Don't ever post a picture of your entire ticket. - I've never had it happen to me, but people can print them and use them. If they beat you to the venue, you will be out of luck, and there won't be anything you can do about it.

Now for pictures