There are many ways to tell a good from a bad conference. My personal definition of a good conference is one where you get more than you invested. To go to a conference you invest time, money, perhaps have to prepare a presentation, socialize and spend long evenings into social dinners. Is it worth it?
I believe that you will bring home little if you just go to sessions. What would be the difference between watching the conference via streaming and being there? So, my general rule is that you have to work your way through each day during a conference: give and take business cards, speak to as many people as you want, drink as much beer as you can (possibly in the company of colleagues, rather than alone). A conference is a place where you socialize with colleagues and look for potential collaborators. My personal strategy, as I matured through the years, is to not spend lots of time at the panels, but at the exhibitions and social events. I sometimes attend panels, if friends are presenting or I need to meet someone in person and I know they are presenting there, but I always get the most from a conference in the socializing spaces. There, you can see the latest books, talk to colleagues, publishers and any other attendants. In the end, your success in networking greatly depends on how people see you as a person. Do they think you are fun, interesting or they can get something from you?
I recently undusted my guitar skills, after many years of a musical hibernation and a friend, hearing that, found a guitar for me in a cold Dnepropetrovsk night, during an international conference. We spent most of the night at a local pub swapping the instrument between us to share our music with two friends. Many other colleagues were present and had fun. It was a long night, we got free drinks and my memories are a bit vague but the next days I could see the sympathetic looks on my colleagues’ faces. We were the ones in charge of fun and many of them had appreciated it. Scientists are also people and, inasmuch as they like to discuss business, they also want to have fun, from time to time. In the end, I think that night was more important for networking than any other activity I could have joined at that conference.
But how can you know in advance that it is worth going to a given event? Or at least on what criteria can you get an estimation to know how likely it is that you will go home happy. There is nothing more frustrating than investing time and money to then go home and think “I’d have been better off staying at home, this trip was not worth my time.”
There is no answer to this question as it depends on your own priorities at a given moment. Sometimes you just need to deliver a presentation at a large conference to please the donor or your university; some other times you know that some colleagues, whom you enjoy working with, are going. Sometimes it is worth it to meet people working in a given university, or country. In some other cases, you know that you will have a chance to publish your work, in other ones you can present your published work.
There are interdisciplinary conferences, regional conferences (gathering anyone doing empirical research on a given geographical area) and policy conferences. In the beginning perhaps, the best strategy is to attend a few and see where you feel more comfortable, where you are appreciated most, where you feel that you can do without. Eventually, the choice of a conference or another also determines where (geographically, and disciplinary speaking) you feel you will have more chances to develop your career. At the European Anthropology Association, you will not meet (so many) political scientists, nor many American scholars. You can thus do your networking exercise with a given category of people from a given region of the world.
In the beginning of my career, I tended to concentrate on international workshops. A conference is a larger investment in terms of time and, possibly, money that I did not want to (or simply could not) spend, not always at least. Workshops were cheaper, there was more interaction with participants and I had more chances to interact with people more senior than I was, to see how they received me. I am still reluctant to go to large conferences but now I have many friends who sometimes attend, and I know I can at least meet with them. Would this strategy work for everyone, I do not know? In the end, it is about finding a niche for yourself, but that comes slowly, as everything else, in academia.