I am having a think about what I've seen/heard of in the weddings I have done that I thought were lovely.
Invites - either no invites or something wacky that can be kept by the guest and used, even if just a fridge magnet. The cards just get thrown away! For a very small wedding, I'd probably do something ceramic myself.
Wedding rings - go as crazy as you like to suit you
Cost of giving notice / registrar - you're stuck with this (and this is my job!) but legally you should be able to get legally married for £127
Wedding dress - meh. Some couples rock up in jeans. Some buy special clothes they will wear again. Wear what suits YOU and you feel amazing in. Don't feel you should conform to a white dress.
Suit - does your soon to be DH need a new suit? Would he prefer and wear more frequently new trousers, a shirt and converse or trainers? If he would, get those new.
Bouquet - seen some absolutely lovely home made ones, some using supermarket flowers. Others florist flowers but hand tied.
Cost of meal / drinks after wedding - this can be what you want it to be! Don't tell the venue it's a wedding though beforehand unless you want the price to quadruple 😆
Honeymoon - this is where I'd spend the money personally
Photos are lovely too to spend money on, but guests can take plenty themselves if you prefer. A video is unnecessary IMO.
Other unnecessary things (IMO) I have seen:
Ice sculptures
Birds of prey
White doves
Over priced wedding transport
Ring cushions
Ridiculous outfits on small children
Phones that people leave personalised messages on
Card letterboxes
Wedding favours
Anything that started as a blackboard
Any elaborate seating plan charts
Order of services
Ring boxes
A wedding venue I work at frequently say that even lottery ticket scratch cards bought as wedding favours get left. They share them up at the end of a shift :-)