Pick up the phone and start dialing.
That is most cost effective method but another good method is face to face with them.
My suggestions would be:
First know what you can offer and idea on cost and why you would be a great choice on those jobs. You need to have it in say a two minute presentation called an elevator speech meaning you can give it in the time you ride the elevator.
Then consider calling them and asking can you talk with who ever does such job hiring.
Then when you reach them explain what you offer and how you can save them money or what ever the reason they should use you is.
I am in insurance and few years back we used a teller marketer for small businesses. She called with very simple line and honestly here it is and it worked very well.
She called from phone book and told who she was and our business name when they answered and then asked could she speak to the person who handled their insurance. (in your case the type of work you are looking for)
Sometimes they just answered the phone and if transferred she introduced herself again.
Then the simplicity was this: I would like to just ask you a couple of questions if you do not mind, most will say okay. No selling here at all.
First was what do you like the most about the coverage you now have. It mattered not what the answer was she wrote it down.
Then what do you like second most and on to third most again writing down each. That was first question.
Then the second question was what do you like least about the coverage you now have and again she wrote it down.
Then what do you like the next least and of course third least.
At that point often the company rep would say they would like to talk with us further on insurance or would be willing to look at options or were very pleased with current coverage. Phone call was less than 10 minutes.
If we ended up presenting to the company we took their answers to be sure we included in our plans the three things they really liked about their plan and were sure to explain the three things they did not like would not be an issue with our coverage option. Those were honest for we had enough options we could tailor the coverage to include and eliminate they dislikes. It worked very well and when we did not end up selling them it still often put us in a very good position with them reputation wise.
You do need a decent business card to leave with them but do not leave them a handful. People may take them but they never know what to do with a handful so they end up in a drawer or the trash. A simple slogan can be good like "you call, we haul" A easy to remember business name and phone number is good. Be sure that phone is answered by the business name and for goodness do not let it be you have reach so and so phone number.
This is a great time of the year if you want to take it to a neat level, if you have access to very good home made cookies or holiday type items have them in simple box or metal tin with a business card on them and stop by the business and walk in and introduce yourself and tell you want to share a great home made treat and a simple introduction to your business. People get real friendly when good snacks are handed to them. Then you have a reason to follow up few day later to ask how were the cookies or what ever and could you wanted to know if they had any questions on your services you could answer.
Please know the hardest thing to do in talking with business on the phone or in person is to know when to keep your mouth shut. If you ask a question the keep your mouth shut till they answer you. It matters not how long it takes them to answer. This is serious. Big difference between you saying I offer hauling and sure would like the opportunity to do some for you and that is it to: Mr Johnson I do such hauling is that something your hire out? Then let him tell you yes or no. If he says yes then ask, would you consider giving me the opportunity to bid a job for you? Or would you consider giving me the opportunity to what ever it is you want to do.... I promise you if you will keep your mouth shut you will get a lot more business than if you do not keep it shut so he is in position he must answer you. If he tells you yes then you may wish to ask, is it okay if I stay in touch with you? If you get yes to all that most likely you have found a person who will be allowing you to bid on his work.
Now if you want to write them instead which is the chicken way out (I know I have been in sales 30 years) do not use letters, use post cards. You have no idea how many letters never get open as they read the envelope and just trash them. Use post cards. Many of those get trashed but they have read them before they are trashed. People even rich people like some of the cheapest items in the world, people like magnets. Magnet business cards you will find on refrigerators, file cabinets, metal dash boards and so forth.
I really hope this helps you. If you want to be professional in this, send handwritten thank you note to each person you speak to regardless of what you though of the meeting. If they said yes remind them of that by saying I really look forward to earning your business or such and mean it. If they were rude still send the note with thanking them for their time and some little softer about your business and maybe as their needs change you will be able to help them and yes their needs are always changing. They grow or get smaller, the company doing it now goes out of business or gets to busy for them or to high in price or something. Of course there are those who are very pleased with who is doing the work and you congratulate them on that relationship and ask them if you don't mind who do you use? The reason I want to know is sometimes I get calls for a job can not do for what ever reason and would be glad to recommend them since they do such a good job. You want to know who the true pros are and that is a great way to.
Realize it got long especially since I told you to have your presentation down to two minutes.
