For people with a vulva, the massager wand is used externally. Try placing the head against the mons pubis or the labia and let the vibration spread, instead of going straight for the clitoris. Tilt the wand so different parts of the head make contact, move it in slow circles, or keep it completely still. The large head means the clitoris is stimulated even when it isn’t directly under the center.
For people with a penis, a wand works against the underside of the penis, along the shaft, and against the perineum. Start on the lowest level, since the skin is sensitive, and try keeping the head still while you move toward it. The scrotum is sensitive to strong vibration—stick to a low level. More about sex toys for penises stands in vibrator for men.
A typical wand head isn’t made to be inserted, and no massager wand should be used anally unless the manufacturer says so. We-Vibe, for example, writes that Wand 2 is not designed for anal use. If you want both external and internal in the same toy, there are double-sided models: LELO Switchhas a ridged wand head at one end and a curved end with an 83-millimeter insertable length at the other, with a motor at each end.