I live in DC, and I can have access to key people. I am clear what is my goal for this next decade. I want to build and maintain a professional network in DC and in my original country. I don't want to just knock doors. I want to strategically know the people to reach, what is the WIFIIT for each network group, and how to maintain the network.
The best networking is slow-cooked, not microwaved. Find events where you can have some kind of regular presence.
Got nothing to lose by going to one-time events as they're good practice for meeting people, but you won't really cultivate long-term professional relationships that way.
It takes time which relies on that regularity aspect. Build trust and don't look at networking as a transactional thing.
The best advice about networking is to show up. And not just once. Keep going.
Sounds really obvious but if you are a comfortable "old shoe" around groups you need to mingle with for business you'll have little trouble talking business at appropriate moments.
This is why more business is done at golf clubs and other hobby locations than in many boardrooms. If you're always around in a good way, and share a common goal or interest in that situation you will become more credible, more trustworthy and thus more likely to do business with.
The real trick though is you have to be genuine. Faking a like of golf and taking three lessons will not work in the case of golf or any other hobby or interest, whatever it may be.
Good networking is about farming not hunting. Try to find people who are also above your own level - more successful, more stable and more helpful. That will have the effect of raising you over time without you even realising it.
https://Meetup.com provides an easy starting point.
You can network.
Study what works + what fails at each event you attend.
Tool your own networking group on what works best.
I've been running Masterminds for years. Periodically I just pick a Meetup event near where I live or when I'm traveling + attend.
Highly instructive, so see how each group works.
So it sounds like your question is really two questions:
1.) How do I find the right people to invite to my network and build relationships with?
2.) Once I define who those people are, how do I go about building that relationship, or network, and how do I sustain it over time?
As for the first question, I would agree with what David said, Meet Up's can be a good place to start. Doing LinkedIn searched with a "geo-filter" for the DC area could be effective as well.
Meet Up's might be a good way to initially meet some of the stakeholders you're hoping to make contact with, but building a strong foundation for a relationship, and maintaining it may be a little more challenging. Not all Meet Up's are structured the same way, some are effectively facilitated, and some are not.
It could be most effective for you to create your own "community building" or "networking" Meet Up that's centered around your own specific idea, issue, or industry, and then go to other related Meet Up's in order to invite people to your own Meet Up that you have more control over.
What I mean by "control" is you can have more control over the "networking" or "community building" frameworks to accomplish those very things. Examples: What is the physical structure of where the Meet Up is taking place? Is it a place that everyone is comfortable and is conducive to community building? What dialogue strategies or protocols could be used to ensure that all parties are heard, understood, and valued to ensure that everyone wants to come back to another Meet Up? Maybe it makes more sense to hire a 3rd party facilitator to help manage this process?
In closing, there are lots of things to consider, let me know if you want to book a call with me and we can take a deeper dive.
I will start by reviewing which group are already operating successful in DC. Even attend a meeting or two. This will give you a better knowledge/understanding of what's on offer. The key benefits they provide for their members. If there is anything missing or something that you can add. For people to join a new group and show up regularly there most be clear benefits for them to see and understand from the out set. Networking is all about Building Relationship and it takes a long time and effort to be fruitful at it. I hope this is helpful.