Get down to their level. When working with a student or a group of students, kneel or squat down so you are at their eye level. This makes them more comfortable, and makes you less of an unreachable authority figure, and more of an approachable helper. Be aware of gender when grouping students together. Don't put two frat boys with a very shy girl.
Some people prefer to make same-sex groups, but that's very transparent to the students.
It also isn't always possible. I prefer to figure out personalities, and pick a nice approachable guy or two to work with one or two women. Vary your examples and conceptual presentations. Different people learn in different ways. One may be a visual learner, one may be a mathematical learner.