diy canapés

Unless this is the kind of thing you do to relax and unwind, I wouldn't, because the last thing you need the night before your wedding is the hassle of making up canapes for guests (also, if you are hiring a venue, you'd need to check they were ok with you doing this, since many venues insist you use a registered caterer because of food hygiene/health and safety etc).

If your guests are genuinely just being fussy, I'd be inclined to ignore their fussing! They can eat what's put in front of them or go hungry. And if their 'fussiness' is genuine food allergies or intolerances, then you really don't want to be messing about with DIY and risking someone being ill because you accidentally cross-contaminated or didn't spot an allergen on the ingredients list. (And if someone has a serious reaction to a particular food, they're probably going to be very wary at weddings anyway so are likely to give canapes a miss whatever you do - I always carry a snack in my bag and make sure I only graze on food I'm 100% sure is safe for me, which is usually boiled potatoes and veg!)

This might sound harsh, but in your place, I'd just tell them that this is the menu and if they don't want to eat it, they don't have to. Grown adults shouldn't behave like toddlers who throw a tantrum because they don't like lettuce!

Are canapes all you are having?

If you're having a proper sit-down meal, maybe skip them?

If that's all you're having, maybe look at sandwiches instead?

If you're doing a full meal post-ceremony and a buffet in the evening, then you definitely don't need canapes as well, so I would just leave them out. Then your fussy folk can hopefully find enough things they will eat at the meal and buffet.