Best practice print white on white on blue

Background.

Not always do I as a designer have direct contact with the printer. That's a fact. So I need to sometimes create two print document files of the same logo, with two solitons/choices for the print guy/girl to print with. And here why.

And question to you, as a printer what do you consider proper way to create this file.

1) One white paper bag

2) a logo to print on th paper bag.

3) the logo is to be printed over/together with a blue Square.  Meaning you either create a logo trimmed on a blue Square.  Logo is see through.

4) or you create a logo with kept white color as been sent to you from your client. And print the white colored logo on top of the blue Square.

My question is what you think is proper and preferable as a print shop guy/girl

How do you like to have the print original made.

Thanks