You have to cross the yarns when you change.
Hold the working yarn over to the left on top of the hanging yarn. When you bring the new yarn up, it will come up from under the one that's being held on top of it and will automatically twist after the first time.
If you need a visual, check out the video on Intarsia knitting.
"Trust the pattern!"
Time flies like an arrow, but fruit flies like a banana.
Hop aboard while we follow the cloud-covered van of knitting harmony, man!! Woooo!! --Hedgehog
IngridKH on Ravelry