Sitting up, aiming cock at belly button and squirting the spunk into that. A trifle playful and extremely erotic. Any other time it's just flat on back with thumb over top of cock which causes a spray. The belly button way though is most erotic: the squishy feeling of rubbing it around is the 'icing on the cake'. If it's messy I have a piece of rag to clean up.
If the woman I am with needs more after I orgasm, I have no problem going down on her after I have cum inside of her. It's not the best taste in the world, but I'm thinking more about getting her off than anything else. I used to have one girlfriend that made it a point to give me a big, sloppy kiss after a blowjob, making sure she still had some of my cum still in her mouth. She said it was only fair. To be honest, it was a bit of a turn on.
I've had it everywhere. One girlfriend used to love licking and sucking my balls while I jacked off, and then she always made me shoot it all over myself. When I was a teen, I spent a lot of time jacking off all over myself as well. I don't know what it is with that, but I would cum harder if I shot it all over me. Made a mess, but I did cum harder. I also ruined bed sheets, carpet, painted walls. I was always more concerned with how big of a load I could get and how far I could shoot it. I didn't care where it went. Hence, I've left several landlords with dried cum all over the carpets.