I attended a class on Caning presented by Mistress Melissa at the Bordello of Decadence (Rosemead, California) last night, and She brought up something I had not seen done before . . .  

Assuming that You've negotiated marking with Your play partner (as the Top) or have agreed to them (as the bottom), there's a technique used by tattoo artists to "set" the ink, which is basically a flat-handed slap/spank on the skin of that area.  So, if your play partner wanted to see "trophies" right away after You are done with caning (or whatever), do a flat-handed slap/spank on that area (wear gloves, if need be, especially with bleeding!) and Your beautiful marks will be much more apparent RIGHT AWAY.  Without this technique, the marks and bruising might take a day or so to show up.

Gloves are important!