Detachable collars, in my opinion, are wonderful. They make outfits so much more exciting if worn right, and there's so many different styles that you can get tonnes of different looks from them. AND they're super easy to make yourself. Virtually zero sewing experience is required and all the materials are things you probably already have in your house or can get extremely cheaply nearby.
What you'll need:
You need very few materials for this. Only:
>An old shirt. Not necessarily white - any colour you choose in fact.
>A pair of scissors
>A needle and thread
>Some materials to decorate your collar such as buttons, studs, sequens or beads
Lay your shirt down with the inside facing up.
Cut along the neck line seam (the dotted line in the last picture). You'll be left with just the neck band and the collar.
There! That's actually the main bit done. It seems far too easy, I hear you say? That's because the best bit is still to come. Decorating your collar.
Decide how you're going to decorate your collar. I used these little metal studs I cut off an old top but this would also look REALLY cute with buttons, sequins, beads, glitter, fabric patches or lace. You can probably think of a whole load of other ways to decorate yours, these are just a few ideas. You might want to use thread that matches your shirt but I decided not to because I quite like it messy. And that's probably good because my sewing is atrocious.
AAAANND that is all. How easy was that?
You can obviously wear this over a high necked top or sweater like I am here but you could also wear it with a low necked top so that it doesn't actually look like you've got a shirt on underneath if you wanted to spice up your outfit a bit.
So there you go!