I started birding comparatively late, mostly because I didn't realize it existed. Sure, I was interested in a general way, and able to recognize all the birds one commonly encounters when going for a walk. Since that's a lot more than most of the population can do I thought I was doing rather well.
This changed when I discovered holidays specifically aimed at wildlife watching (what an eye-opener in other ways too), and I met more people with a deep interest in wildlife. I realized that my abilities made me a rank beginniner, but I also got a glimpse of what is achievable. That certainly made me want to become much more accomplished, if only because clearly other people were seeing more than I saw.
I don't entirely agree that going out with binoculars and just observing is the best way of improving. That's what I'd done previously, and while it had taught me that a glimpse at a bird with a pale rump flying off could be identified, there were so many signs I was missing because I wasn't aware of them.
I started making much bigger strides when I was able to learn from other people. I did a couple of courses (because I didn't know anybody locally who shared my interest), and they made me change how I looked at birds. The first one was on raptors and concentrated on discerning the shape of (a potentially tiny) silhouette, and working from there. That was another eye-opener, and when I realized after returning from that course that I could tell that the bird that I'd only just caught a glimpse of was a sparrowhawk rather than a kestrel because I'd seen enough of its shape to be sure of that I was hooked.
I think one needs to acquire this level of looking at birds before one has any chance of sorting out (possibly hundreds) of new birds abroad. I was fortunate with my early nature-related trips since they were to comparatively species-poor countries, and so my lack of experience didn't stop me from picking up most of what there was to be seen, but a subsequent trip made me feel ill-prepared (although I had studied the field guide, compiled my own potential trip list, including locations), because I wasn't a good enough bird watcher, and because I hadn't tried to learn any of the vocalizations.
I did those courses and learned more and when I travelled to Namibia having been to South Africa before it was immensely satisfying to be able to identify birds to family based on the ones I'd seen on the previous trip. It certainly helps a lot with identifying birds if one knows where to look in the field guide. Meanwhile I've met more people who've been willing to share their experience, and they have helped me improve.
A lot of the trips I've taken were for general wildlife, and the guides were not necessarily well-versed in birds, so despite the fact that I've been mostly on escorted trips (I lack a network of people to go on self-organized ones with), I've done a fair amount of trying to identify my own birds. I'm now fairly good at this, but the trip to Kenya last summer made me realize that, for example, cisticolas were beyond me at that stage (they weren't vocalizing, in the field guide there are lots of possible species that look very similar, and what is written there about habitat wasn't enough for me to be able to narrow the choices down). It would probably take help from somebody to get me situated with some of these birds for me to learn what to look for.
So my advice would be to try and go bird watching with more experienced people occasionally, and to ask them about what they are looking for, and how they can tell at this distance that the bird they've just called is an X (and not a Y or a Z). This can help a lot with speeding up one's learning because it gives us an idea for what to look for. It can open up a completely new perspective.
Andrea