Here's some, but I'm no expert - wife is!!

Try sucking on an ice-cube just before, or mint ice-cream.

You can pay particualr attention to the frenum and the ridge.

Not tried it but Champagne is supposed to be something else.

My wife lights my fuse, by catching me unawares - somewhere in public or when we might get caught. She like to start slow and whilst getting it going undo her blouse and expose her breasts (in her bra) and the slowly unhook each shoulder strap and release each breast from her bra. At the point of cumming she pulls away, to get a stream on her face, and then take my cock back in to swallow with the string of spunk running down her beautiful face.

Have fun and enjoy

Andrew