Create a Twitter account based on a certain niche, maybe about baseball, or weight loss, whatever you want, I prefer to go with what interest me, like a hobby.

Go to Twitterfeed.com and sign up for a free account, I'll discuss this later.

Head on over to adf.ly, and click the "JOIN NOW" button near the top, fill out all the necessary information.
At the bottom of the form, make sure your account type is set to "link shrinker".

adf.ly only pays through PayPal or Payza, so be sure you're signed up with one of the two.

Okay, so now what you want to do is go to Google, and search for any website that posts information and updates about the specific niche that you chose to base your twitter account on.

When you find the site you want, look for something on the page that will link you to that websites RSS feed, If you have trouble finding if they provide feeds or not, you can either go to "FIND" or "SEARCH" located in your browsers toolbar and type RSS in the search box, or enter the web site address in Google and add rss after it.
eg: gamestop.com rss
This will usually bring you to a page where you can select what rss feed you want, some sites offer multiple rss feeds so select the one you feel fits your needs.

On the same screen click the "Advanced Settings" button and go to "shorten link through", there is a drop down box beside it, open it up and scroll to the bottom and select "Custom", Leave it empty for now and go back to Adf.ly, while logged in to adf.ly go to the top of the page and click Tools, on the tools page go to "API Documentation" and click.

On this page you will see a link that looks like this http://api.adf.ly/api.php?key=################################&uid=######&advert_type=int&domain=adf.ly&url=http://somewebsite.com

# represents your id and key.

Now take your key and uid and place it in this link (replace the # with your key and uid)
http://api.adf.ly/api.php?key=################################&uid=######&domain=adf.ly&url=%@

http://somewebsite.com Must Be Replaced With %@ In order for this to work.

Also you may have noticed that in the modified link "advert_type=int" has been removed, this is because TwitterFeed has issues showing the interstitial ad (full page ad) and just leads to a dead page when clicked, or shows the ads but doesn't redirect to the desired page, so the only way to fix this is by removing the "advert_type=int" instruction from the link and adf.ly will automatically use the interstitial link instruction and will work properly with TwitterFeed.

Now when that's done, all you have to do is copy and paste your new link into the twitterfeed Custom endpoint box and "Continue to step 2" on twitterfeed.

"There are more advanced options that will serve you well, but you can play around with that on your own time."

Make sure that you are logged in to the twitter account that you want to use with twitterfeed, you are going to want to activate your twitter account with twitterfeeds oauth so it will automatically post feed/blog updates to your twitter account using the rss feed that you provided to twitterfeed, when that's all done, click done at the bottom, twitter will now get updated feed posts from twitterfeed, and the links in each post will now be automatically shrunk using adf.ly and posted to your twitter updates, and every time someone clicks your adf.ly link, you make a bit of cash.