It takes practice. I get better results if I make a test piece with the fabrics and batting
I've used for the quilt. If there is a pieced border (lots of seams on the edge) I have to
reduce the seam width or cut wider strips. I found it quite a bit tricky when I made a
QAYG that had different thicknesses on the edge. I think I learned a lot from that quilt.
It helps to sew the binding as straight as possible. Put a few pins and sit straight in
front of your machine. I highly recommend the video which Holice made on binding.
You can bookmark it. The site seems to be down right now (for me anyway).
http://www.quilterstv.com/channel/video/134
Don't worry if you miss a few spots. Most of my quilts have a few spots where I missed and have to touch up with some hand sewing. I'm getting better though, so will you.