I HATE miscellaneous stuff! I really like to have a place for everything.
I don't have the answer to it all but:
the tool for removing the SIM from my phone, spare rubber bits for ear buds
These should go in the 'gadgets' drawer, with charging cables, your ear buds when they aren't in use, and accessories that belong to your phone/laptop/tablet.
an Allan key I used to tighten up the bed every so often
Does it need tightening now? If so, do that first, then it goes with your tool kit, screwdrivers etc
a save the date card
Pinboard, fridge (with a magnet) or write the details on the wall calendar and bin the card
a jewellery makers card
Take a photo, dispose of card
ear plugs
Do you use them? If so, keep them there, preferably in a cute little case (order one off Amazon if you don't have one). If you don't use them routinely but there's a chance you will use them for travel put them in the zip bag you have your passport, plug adaptors etc in. If you never use them, bin.
a hair bobble
Do you tie your hair back? If so you must have more than one. Where are the others? Repatriate it! I have a cute decorative tin with all mine in that lives on my dresser. If you don't tie your hair back, bin it.
a small brush for cleaning a razor
Again, do you ever use it? Presumably you don't shave in the bedroom, so have it wherever the razor is!
half empty paracetamol pack
I have a cute zip bag that I keep the packet in, that lives in the bottom drawer of my bedside cabinet.
a decorative snake
He's not decorating anything in your drawer! Does he spark joy? If so, pop him on a shelf or somewhere on display, if not, charity shop or bin.
my prescription exemption certificate
In a flimsy in a ring binder marked 'Important certificates' with birth and marriage certs etc
the thingy I found under the dresser I've been looking for but not yet put back in the thing it goes in
Put it back where it goes RIGHT NOW! If you struggle to do stuff like that set a 2 minute timer on your phone, or play a motivating song, and challenge yourself to beat it
Sorry, I realise you're meaning generally, not asking what to do with these specific things right now! The fact is though that if these specific things have 'a place' then maybe all (or nearly all!) the other random miscellaneous bits can do too? I have little storage tins/boxes/folders/decorative zippy bags for nearly all my little bits and bobs. They're not always in them, mind you, but at least they have somewhere they officially belong. My random uncategorized stuff goes in a plastic 'Really Useful Storage Box'. The smaller things go in tiny little ziplock bags (again you can get them off Amazon) first.
OP, you are motivating me to have a look at my things and see if they can be better organised! I'm going to get to it now! Thank you!