Using the right blanket can really make a difference in your swaddle. Using a blanket that's too soft won't grip to itself to help it stay wrapped around your baby. Using a blanket that's too thick can make your baby over heat. I have found that these muslin blankets are perfect.
I use a different swaddling method than what is on the packaging. I fold down one corner about 8 inches. I then pull the left side over the baby, while holding their arm down. I tuck that piece under her back. I do the same with the right side. I make sure that its pretty snug. I then take the bottom, open it up so that its one layer, fold up the corner, and pull that directly up so that its over her chest. I then wrap the ends under her sides. There should be little 'wings' on each side. They should wrap around just enough to be on her back so that if you lay her down, she is laying on them, and securing the swaddle with her weight.
There are many different ways of swaddling. This is the method that has worked best for me. It was a blend of the 'Happiest Baby on the Block' method and the method that my pediatrician uses. Experiment with different ways that you have heard about and I'm sure you will find one that works best for you and your baby.