I used to have a bit of a fixation with facials, but I've always found CIM to be a bit uncomfortable. I get so sensitive when cumming that it can actually feel painful, especially if the girl keeps on sucking like a Dyson. A shot across her face and then a few shots into her open mouth, however, can be very sexy. For some reason I get a kick out of actually hearing my cum hit the roof of her mouth.
Lately, however, I have been keeping things simple - cumming inside the girl's pussy. I find it is a more satisfying climax and avoids the fumbling to whip off the condom at the critical moment. Finishing by hand over a girl's face can be great, but you can also fall into the porn movie trap and find that you're tugging away frantically trying to cum, having thoroughly desensitised yourself!