I agree with Neoow regarding no shoulder time if he's a biter.
It's all about learning to read their cues. My new rescue bites whenever he's on or near his cage. He was cage bound for 8 years, so he's extremely cage protective. Once he's away from his cage, he's very anxious, so I must make all movements slowly so as not to frighten him. I will not pet him yet. For now it's all about getting him used to perching on my hand. Once he's completely comfortable with that, I will watch his eyes and feathers for signs that it might be the right moment to introduce stroking and petting.
Again, it's all about Grey time. If you can't respect their time, you and your family will get bit. Simple as that.