Fitted Cot Sheets

We have recently brought a cot which has a mattress of a different size to most cot mattresses, therefore all of the fitted sheets I have found don't quite fit either in width or height or both, some are too small one way and too tall the other way.

I was just wondering what people have found works best either using a too big sheet, slightly too small or just using flat sheets instead?

Any assistance would be greatly appreciated before I go out and buy any sheets.

Thanks

If you cant find fitted sheets that fit properly, you could buy a set slightly too big, unpick the elastic and tighten it enough to fit better, then sew it closed again? Its actually quite simple, I did it for DD's toy barrel by hand (wasnt the design I wanted, so bought some material and hand sewed a cover for it with elastic around the bottom to go over it like a fitted sheet would)

We've got an old 'standard' size cot, and new mattress from baby factory. They only sold fitted sheets for the american size cots. Which are a bit bigger.
I always planned to adjust the american size fitted sheets, but never got around to it. They fit fine, I just have to tug them a bit further under the mattress.