I could of titled it "How to Make Friends" but I'm not a expert or anything close on making friends in WoW or am I a real socialite (see Haris Pilton) at it either. However I do make a lot of friends in WoW and often its from PuG instancing. Much of the Friends that I make come from the fact that I just plain PuG allot. Some my guildmates are so afraid to run instances with people they don't know they only run with guildies. Ask if they know anyone else, most the time they don't know other friends and its obvious why.
Lets stroll back down memory lane a bit. I'm a avid solo player just my style. When I hit 70 I had (0) friends on my friends list. Was that a problem to me, NO! Because I played the solo game and was good at soloing it leveling while I mastered the art of tanking tons of mobs for fun and kicks and learning how to master playing a Protection Paladin. I was often guildless. But at 70 when it was time to gear up and run instances I had (0) friends and had no guild to lean on. So I learned to look in LFG channel and ask in /4 and /2 for LFM for regular 5 mans and then later on after that 5 man Heroics for groups.
Over that time I've made a lot of friends on my server. That's an understatement as well. I've made so many friends running PuGs that you notice that their is a cap to how many friends can actually fit in your friends list. Yes it has a limit where you can't add any more friends. So often when I make new friends I've had to unfortunately look down my friends list and decide who I haven't seen lately and remove them as friends. Had to just so I can add new friends to my list. Yeah that's a good problem to have, so many friends that you have to delete old friends to make friends for new friends. Do I bother my friends, No. But when i'm I need to fill a 5 man group they are my go to list first.
Now I don't understand how some players say they have a hard time making friends. I can only say you need to get out more from under your own guild and run instances with other players and hopefully add a few friends. "Yeah, but I hate to PuG with people I don't know". Hey whatever rocks your boat that's up to you.
On my daily instance PuG runs I often add new friends to my list of people that can play their class well or who appears to be good ok players. Everyone starts from somewhere. But I add new players all the time to my list. However at least 20% of the people on my list are all fairly good healers and enjoy getting better at healing. I have less dps friends on my list, dps is everywhere but yet quite a few good dps players are on my list as well. Of all the people on my friends list they are scattered across many of the top raiding guilds on my server and other guilds. Now if you can't see value in that with friends then not sure what to say.
For instance the guild I applied to a few days ago I know at least 5-10 people in that guild (I was approved, however I haven't decided). Several of the people in that guild on most regular days are in at least one of my daily Heroic run, so I know some their members and they me likewise. That factored into my application when I applied to their guild because I was known on the server to some degree. Some of their members had alts that I also ran with that I didn't even had a clue they were in the same guild. But if you don't get out and do a Instance run here or there you lessen the potential friends you can make. Many of my friends have me on their list as well of friends when they are looking for a instance and need a potential tank. As a tank I never have a problem finding a group but its good to have friends. My all time best healer was a Resto-Shaman I found in a PuG, we ran many Instances together that helped us both. You never know the friends you will find and where.
You can make friends in your business dealings. I always need enchants or JC services and other things. When I find a good enchanter and one that has many enchants that I may need I pay them well for their service even though they don't ask in any way or demand a said fee. I also put them on my friends list for later service needs so when I need a enchanter so I can easily find them. Many times I've used the same enchanters over and over or another on list if one is not logged on. Those people get to know you over time. When you ask for a favor your not some random unknown person they don't know. Often as said before many those people happen to be in top guilds other than my own. In short you can call that networking. Do I use my guild enchanters yes a few times but my guild is quite small. Often I use the enchanters that I have dealt with before. If I cant find one I find new ones for my needs. its building relations with others and making friends in the process.
Sometimes you can help a person out on a quest if you have time. Though its not my usual way of making friends its a way to be known my many others by supplying your time. Who knows you may make a new friend. However I don't get asked much to help on many quests unless like Ring of Blood in Nagrand or something. The thing is you have friends in your guild that become friends by mutual association of same guild. You can make friends by helping out others on a 5 man Instance run, you find lots of new players at the level cap that way. You can find some very good players in Heroics you may never know exists that can potentially make your friends list or recruit list. You can meet people through your business dealings.
All are different things you can do to meet new people or friends, but if you never do anything different you will never know who you will or won't potentially meet them. At least that's how I've met all my friends and I have quite a lot. I'm also quite well known on my server too. Thanks to PuGs. Yeah I know, you hate PuGs right.