If you want to get best one-way links, there are two currencies with which you can pay:
Money (Dollars, Yen, etc)
Time and effort
The first one is the easiest, but unfortunately not everyone has money for links, especially expensive links that reach $1000. The second currency is a harder path, but it gets you to the same goal. The second currency also supplies you inevitably with the knowledge, experience and character to finish what you've started.
Relevancy
You are more likely to get a link if you provide a URL to the relevant section of your website. You are also more likely to get a link if you suggest a relevant page from which to get the link. This creates relevancy, which implies you've reviewed their site, read their content and believe that you can truly benefit their readers. Of course, a brainy webmaster knows exactly what you're after, but it shows commitment and differentiates you from others.
If what you're proposing is truly relevant, then your chances of success increase dramatically. The trade off for this is you actually have to read websites and figure out the best places from which to get links.
Email Headline
The headline is one of the most important pieces in copy writing. Which of these would you open?
Profit Online With Internet Marketing Techniques
OR
Why Most Marketers Overlook the Single Most Important Factor in Making Money Online ...Plus, The ONE SIMPLE THING You Can Do to Grow and Profit Faster than Everyone Else
(I stole the second one from "The Great Copywriting Conspiracy" by Clayton Makepeace)
An email's headline is just as important. People make decisions as to whether a particular email is spam by reading the headline, so something like "Link Request" is likely to get deleted, while "A suggestion for your website," "article name," etc is more likely to be opened, because it's a suggestion and it cuts to the chase, stating the actual article (page) name (or URL).
Offering Unique Value
This one is a complement to the above paragraph on creating a site with high quality content. You can also create applications that people need, interviews and other linkbait. Then email different webmasters mentioning your cool additions and suggesting how they can benefit their users.
This is a lot easier once you already know some people through forums, blogs and chats, which brings us to the next topic.
Online Community Involvement
It's easier to get links if you already know some people in a community. They may mention you on their pages/posts, and are more likely to link once you offer linkbait. They can also help you spread the word by offering feedback and reviews.
Imagine a new person on a forum posting a link to their new linkbait. Now imagine a person who's been around on that forum and knows some people. The latter is likely to get more feedback and links, because there's a degree of social psychology in forum interactions, as with anywhere else in life. The new guy is not yet "accepted," while the old one is a familiar "face."
Treating Link Requests as an Email Campaign
The biggest Internet advantage is the ability to test at no cost. Test your email requests and optimize them as PPC landing pages or email marketing messages. Send a batch, and then track results. Send the next batch with a few changes, and then track results. Send a third batch with more changes, track results and then compare the two. Stick to what works, and drop what doesn't.
Conclusion
Reciprocals do not work as they used to, but one-way links work. The conversion rate depends on your approach, headline, and most importantly your site content. Focus a good portion of the budget/time/ effort on site development before you engage in link building, and the process will be much easier once you get to it.
Link Trading 
