How to join garter stitch border to stockinette stitch garment neatly?

New to the forum. I’m knitting Debbie Bliss "Baby Bolero."
Directions say “sewing in place as you work.” I have tried several different stitches and it doesn’t look neat. Suggestions?

Thanks,
Kathie

Never mind! I just found answers to my question in a previous thread. Glad to be here!

Kathie