There is no absolute truth, you have to see what example works better for each case.
Yes, i think starting with a research on targeted businesses/clubs will be the best idea, then you can try to apply some of these cases.
I let you my bible:
Call them - Get them on the phone. Make them hear your voice and know that you're a real person. I did it with some clients and i got great results.
Sometimes a good comment on a blog that makes a difference can help you build the relationship you want.
Interviews-Normally companies like to be interviewed, so take the advantage of this and make some. Remember to give them a mention when you gonna share that content on your social networks, they will be happy to share it.
Random acts of kindness - Whenever you can, be nice to people. It might just payoff. Always be on the lookout for helping those in need. These random acts can turn into lasting relationships.
Give a crap - Actually care about people. Show them you're not just a bot with a picture, but that you're somewhat human. If they share on Twitter that their daughter just graduated, congratulate them. Something as simple as that can open up your chances to build a relationship in the future.
Participate - If someone is conducting a survey or testing something, get involved and participate. Those are great chances to start conversations with new people.
Local meetups - Whether you find one or start one, meetups are a fantastic way to get to know people close by.
User group meetings - A great way to get to know people who think like you is by finding those who use the same products or services like you..
Conferences - Seriously, go to them.
G+ Hangouts/Skype - Be the first person to use a Google+ hangout! But seriously, that or Skype is a great way to meet face to face with someone without actually meeting face to face (if that makes any sense!).
Twitter RTs, Responses, & DMs - If you want to get to know someone on Twitter, first retweet them a few times. Then respond a couple times to a few of their tweets, then continue the conversation as direct messages. Finally, ask to email (because 140 characters is never enough), and now you've got the ball rolling.
Answer questions - Answer questions on Twitter, Quora, and anywhere else people hang out. People ask questions all the time. These external opportunities are a great way to put you on their radar.
Note: don’t think of it as a short-term input & short-term output, especially if you’re a marketing agency. More so, realize that these relationships can be tapped into for multiple links (i.e. for different campaigns, clients, etc.), as well as for other marketing opportunities (i.e running a joint-contest).
Regards