I'm assuming you mean mitered
binding not mitered borders. If you mean borders, please let me know & I'll post different links.
Hands down,
the best tutorial I've ever seen on mitered binding (and borders) is Bonnie K Browning's class on AQS iQuilt. She is so clear & easy to understand. I just love her! They're running a promotion right now that if you type in the coupon code
IQ25 you get 25% off the price of the class -- plus, if you're an AQS member, you get an additional 20% off that (final member price is $18).
https://www.iquilt.com/course/border...shing-touches/
Among the free classes, my absolute favorite is a 4-part series by Sherri Driver on the McCall's YouTube channel.
Joining the Strips:
https://www.youtube.com/watch?v=7Hha94oe3XA
Machine Sewing Binding to Quilt:
https://www.youtube.com/watch?v=X2MJdPFzSbE
Joining the Ends:
https://www.youtube.com/watch?v=3w5npghs4V8
Turning & Hand Stitching:
https://www.youtube.com/watch?v=E6lvBzEqq1o
The main piece of advice I would share, though, is that you need to sew to 1/4" from edge of quilt, backstitch & then take the quilt off the machine. At that point, you'll fold to turn the corner & start stitching with that backstitch to secure the seam. I've certainly seen people who do shave off a tiny bit of the binding before turning their binding to the front to hand stitch, but I've never had luck with that. I just follow the directions in the tutorials & then make sure to stitch the corners closed -- which both makes them more secure & makes them lie a bit flatter.