You knit into the front of the stitch, but don't drop it off the needle. Then knit into the back of the st, keeping it on the needle still. Knit again into the back of the stitch and then slide the whole thing off the needle.
You now have three stitches where one was before. You turn your work around and purl into these stitches to make the bobble bigger.
"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