I did better than giving you the explanation, I gave you the means to find the explanation for yourself. The best secrets in magic are not floating around the internet for anyone to see, they are well hidden in books.
I'd recommend getting Gravett and Hugard's Encyclopedia of Card Tricks (the force is on page 30) you can find the book on Amazon
HERE for $12. That book has a lot of great effects that use limited sleight of hand. If you want a book that contains advanced sleight of hand, get Hugard and Braue's Expert Card Technique (the force is on page 271) which you can find on Amazon
HERE for $10. Either or both books would be a great addition to your magic.
If you get either of those books, I'd be glad to share my tips on using the force with you. Those tips take a good method and make it great. As you can see, real secrets aren't free, you have to put some effort and investment into your magic before others will put effort and investment into your magic.