I've been hooked on pair programming from the time I first tried it. I love pairing as a way to transfer knowledge (either about technology or about our product), build motivation, and build teams. Software development is a long series of decisions both large and small, many of which could plausibly go another way. When I'm soloing it is so much easier for me to get stuck on any one of them.
If you are in a company where pairing is the norm, you'll do it, but what if people are just curious about pairing? Or willing to try but who don't know much about it? Here's what had worked for me. First of all, I invite people to pair for 1.5 hour blocks, usually scheduled on our calendars (shorter can work but to go longer (a) requires a break in the middle, and (b) requires more buy-in from my pair than I sometimes have). Secondly, when I'm asking a co-worker to pair I ask them to pair on a specific task which I am up to speed on (for example, which has been assigned to me). Ideally, the task also requires knowledge they have that I don't (familiarity with a particular part of the codebase for example).
During the pairing I apply pairing skills I've learned over the years (for example, handing the keyboard to a bored pair or saying "let's give it a try and see what happens" rather than "that won't work"). I wrap up by the end of the scheduled time (continuing after a break if both people are psyched is an option but usually 1.5 hours is quite enough for people who aren't in the pairing habit). As we wrap up, I make sure to thank them and tell them how helpful it was (this is usually quite sincere - I did mention that I go faster when pairing than soloing, didn't I?). If the task isn't done, I usually finish it up soloing (especially if the remaining items are fairly straightforward once pairing makes some of the bigger decisions).
Afterwards, I tell others, for example in a retrospective or a 1:1 with my manager, how much I enjoyed pairing and/or concrete benefits like "we were able to work out the interface between these two components much more easily than if I had been soloing on one side and you had been soloing on the other". The goal here is not to tell people they have to pair, the goal is to make it feel like they are missing out on something great if they don't.
Pairing got one of my teams out of a sticky trap. There was a section of the code which only one person understood. We saw this was a problem and the person who knew the code wanted to share his knowledge. For our first attempt, he explained it in a conference room with a whiteboard and a projector. Perhaps that helped a bit, but the explanation didn't made as much sense to the audience as to the presenter and we adjourned with confusion and frustration, or at least with limited comprehension. Later I had reason to do something to that code, and so I asked the expert whether he would pair on it. Mechanically, it was miserable. We didn't share a fluent spoken language and he used a customized setup (using vi and virtual machines) which meant that I mostly watched him type or told him what to type. A far cry from the easy flow between two people which sold me on pairing in the first place! But guess what? I learned a whole lot more about that code than I did from sitting in a conference room. Other people started working on that code and the person who had been the expert could get help and feel less alone. Here I started to formulate my belief that even a very small amount of pairing was better than none at all.
In my other example the surprise was even more pleasant and delayed. We were in a company where pairing was often mentioned, sometimes practiced (at least in some teams or situations), but was certainly optional and not part of most people's habits on a regular basis. One of the people on my team was nice but also seemed like a loner: often wearing headphones, not speaking up much in meetings, and getting a lot done but in a heads-down kind of way. Not my first choice for someone to ask to pair. But in a few cases, I carefully came up with a focused, suitable task and asked him to pair. We paired maybe half a dozen times (if that) over a one year period. It energized me and I appreciated his willingness to put up with my eccentric desire to pair. Fast forward a year or so, we now work for different companies, and he tells me that pairing with me was one of the highlights of his entire two year time at the company! I was floored. I knew I enjoyed working with him in general but I was completely unaware of what he was getting out of pairing.
Do I recommend being a pairing pioneer? Well, it isn't always easy and to be perfectly honest, my current job search is for a situation where pairing is already more established and common. But if you like pairing and find yourself in a non-pairing or low-pairing situation? Sure, give it a shot. As long as people approach it with an open mind (on both sides), the only thing you are risking is 1.5 hours of your time.