I think my attraction to feet stems from my desire to tickle them and I don't think it would be there without this over-riding tickle fetish.
Given that it's one of my favourite places to tickle, I think it also explains why I like shoeplay so much as this is a teasing reveal of an area that I would like to tickle in someone...
The turn-on from that glimpse of the specific body part is linked more to my tickle fetish than it is to any body-part fetish. Similar to when a tennis player throws up a ball to serve and the underarm is exposed.
I probably do have some similar thoughts to a foot fetishist when it comes to feet... for example, I'll see a friend wearing black tights in converse hi-tops on a hot Summers day and I'll be thinking "wow I bet her feet her baking in those", but this stems from my desire for her to take the boot off so the feet are tickleable...rather than thinking how much I'd like to smell her feet or whatever. So the end result (or intended result) is different, but I am definitely aware of an overlap... I notice things like how socks cling to feet when they're taken off if the feet are warm and how sweat patches can be left on certain floor surfaces etc - I think I like to have knowledge of someone's feet when I tickle them....almost like a back-story and I think it's almost an ownership thing.
While I enjoy looking at feet (bare or socked) and comparing shapes/colours/toes/sizes etc, it's more a general appreciation for them as an attractive part of someone's body if looked after properly - I have never really had much of a desire to lick/sniff/suck or worship feet in any way and interacting with feet would not normally form part of my sex life, unless tickling them.
Whatever involvement I have with feet, the dominant thought process and what it all eventually boils down to is tickling them.
Complex indeed, but overall I therefore think tickling reigns as the dominant fetish for me. I'm certainly aware of people who love tickling but do not have the fetish for feet - it's just a neutral thing - tickling a body part because it's ticklish - and if it's not, then move on to one that is. And, vice versa - sucking some toes, licking a sole, sniffing some socks...wow! but tickling the foot....what? Why would I wanna do that...