Either don't bring them up, bring them up sparingly or present them like someone who doesn't have your fetish would, usuallt as an embarassing drawback or obstacle.
If your thing is tentacles, add in a squid- or octopus- people. They're weird and smart, it creates a sense of alien-ness indigenous to earth.
If you're a lolicon, having hostages or young girls In danger increases the emotional stake, because young girls are perceived to be more innocent.
If you're into vore, then hey, monsters swallow things all the time. Perfectly normal.
And if you're really degenerate, you show uncensored handholding between multiple partners and never explain it.