Something Old is an easy one and can quite often be Something borrowed as well.
for example a necklace or earrings from your Grandmother or Mother. It could also be that you have hired an old car.
You might have a keepsake locket with an old photo of someone no longer with you and have that tied into your bouquet.
Something new – well there is lots in that department, new dress, new ring, new shoes, underwear.
Something borrowed – a piece of jewelry, your veil.
Something blue – most common a blue ribbon on your garter, but maybe for a tropical bride a beautiful anklet with blue beads or stones. blue jewelry or I know a beautiful friend that had blue shoes.
I also lent another very special friend an antique rose gold bangle gifted to me from my Mother that had a blue opal in it. So that incorporated Old, borrowed and blue.
My daughter wore diamond earrings that were made from diamonds from her late Grandmothers engagement ring.
So there are lots of special ways to incorporate the old, new, borrowed and blue into your wedding day just some creative imagination and some special people to assist you with it and perhaps loan you something of theirs for your Wedding Day.