Firstly are you on an NA or EU server? This is important because you can only play with people from your region.
Secondly what is it about the LFG tool that’s disappointing you? I know it confuses some people who are used to other games because it doesn’t put you into a group automatically, all it does it allow groups to advertise for more members.
If you don’t see a group offering what you want I highly recommend putting up your own advert. I’ve made the mistake several times of thinking because there’s no listings that are right for me (or none at all) that there is no one for me to group with. Then when I do try making my own listing it fills within about 15 minutes! I think, especially for casual players or 1st timers, there are a lot of people who want to join groups but are unwilling to be the one who starts it off, but when someone else takes that step they are there waiting.
I also recommend asking your guild members, even if they’re not dedicated dungeon guilds. Yes many of the individual people will come and go, but if the guild is in any way structured new people coming into it should be reasonably like-minded so you’ll still get a consistent experience. (And GW2s dungeons are not the kind of thing where it’s so difficult you need to practice regularly with the same group of people to be able to do it, even LFG groups that have never met before can be pretty confident they’ll complete it.)
Danielle Aurorel, Dear Dragon We Got Your Cookies [Nom], Desolation (EU).
“Life’s a journey, not a destination.”
