On a bed

Lying face up, double column tie ankles with long rope and attach above head with taut line hitch.

On a chair

There's an ingenious trick I learned from Mike West, at Shibaricon many years ago, which is that you can do this in a chair as well -- often even an implausibly-small seeming one, like this:

Don't ever walk away from someone tied like this. They could very easily knock over the chair and/or get into a position where they're hurting their neck. You'll notice in the video, I'm starting to untie her where I cut it at the end; I got her untied and back to a normal sitting position before I stepped 6' away to turn off the camera.

I recommend using a chair with some padding. The one shown in the video was not especially comfortable. They're also, incidentally, terrible chairs for sex; I've broken several of that design.