Read this...
How to throw a jig, a step by step walkthrough - Bloodydecks.com
Although there is some good information posted by the author of this write up, I believe that the response by the member "Moleculo" a few post down has some better points than the author. Check it out, it's a good read...
Oh, and for the record, if you practice, you will always get a farther cast with your jig down by your reel. I would say read the article I posted for you and consider the video I posted as well. Stop practicing with your jig only a foot from the tip of your rod, and start getting used to casting your iron with the "pendulum" effect. You will get much farther.
Also, the video I mentioned can be viewed for free by signing up for a 7 day free trial at TotalVid.com.