The super-fun thing about fetishes that involve everyday items is that your play doesn't have to be limited to the bedroom; you can take it out into the world completely innocently. So, the first thing I thought of when I saw this question was "Definitely show up for a date wearing Keds!" Don't say anything or do anything out of the ordinary, just have them on and make sure he sees them. Then go out. From there you have several routes you could take: You could go somewhere with long tablecloths where he can't see your feet but he'll know the Keds are there the whole time, or you can go somewhere where they will be constantly visible to him (maybe somewhere with bar stools?). Either way, the idea is to allow excitement to build throughout the date. In the bedroom, shoe fetishes are fun because they are, in my experience at least, pretty easy to cater to. Just try wearing the shoes in the bedroom. If your sexual play involves things like lingerie, add the sneakers! If not, naked and the sneakers! Even if you have a super-sexy outfit that you wear when it's seducing time (I think a lot of us have this) put the sneakers on with it. As your partner hasn't experimented much with it, he may not know the nuances of what he enjoys in terms of this fetish yet. But, if it's all visual, it may just be about wearing them. If it involves touching the shoes, you can incorporate some playful teasing into it. Maybe you make a rule that he can't touch the shoes until you say so, or he can touch anything but the shoes, or the shoes are a reward of some kind.
Play with different scenarios, figure out what you both enjoy and have fun with it. There are tons of possibilities here!