I'm like you Sunnie ... I don't quite trust the Lock Stitch on my machine. Yes it's supposed to be enough, buttttttt!
For now, I've been doing like KR, bringing the bobbin thread up, do a lock stitch at the start and then later, take them to the backside, tie the tails together a couple of times and bury. Whether it's right or wrong, I'll be following this thread to see what I can do better!