Aspect Ratio Guide Solutions

Has anyone come up with a great solution for filming with aspect ratio guide lines?
I'm looking for something practical without using an EVF.
I've read about:
. clear scotch tape
. 3M static film cut in strips
. black electrical tape(yikes!)

Please do tell.
cheers.

Duct tape!

No, not really... DO NOT put duct tape on your screen!

Hmm... Reminds me of late news anchor Jessica Savitch on the Letterman show many years ago... she had a problem with the hem on her skirt or something, and Paul offered a roll of duct tape.

She said, “You musicians and your duct tape... mends everything but broken hearts.” {snif}

Dave offered to tape her knees together, and it kind of went downhill from there.

Am I off topic?