How to use "costume" in a sentence

'My costume will be a secret

I began to get worried about my costume

It was a drawing of a costume which I had sketched and then thrown away.

I was going to keep my costume a secret.'

'Then I suggest that you have your costume made in London, Madam

I was glad that I had chosen my costume at last

Maxim and Frank asked me about my costume but I told them nothing

There was Giles in his white Arab costume

'Why, about your costume