Self-portrait focusing solution

I've attempted lots of self-portraits in my studio, usually whilst setting up my lighting for a portrait session. Using the self-timer on my 1DsM2 I can obviously get out from behind the camera in time to get situated, but the problem is how to focus. I like using the largest aperture I can, so the focus becomes rather critical, and of course auto-focus isn't an option because the focusing is done at the time the shutter is pressed, not when the timer interval completes (who decided that was right?).

Anyway, my solution is to use a roll of white gaffer's tape hung on a lightstand, focus on it, mark the position on the floor, then move the lightstand. Probably no news to you old-timers, but it works for me. And voila! A well-exposed, in-focus photograph of a rather unappealing, yet well-meaning photographer.

Hi, Steve,

That's called "hit your marks".

And a nice self-portrait.

I know one photographer who sets up portraits with a balloon on a stand that has a boom attached.
He clamps the balloon in place, with the stand directly behind where the subject will be standing, he sets his focus and removes the balloon.

The subject can talk into shot, slowly backing up until the boom touches the back of his head.
Take the shot, job done !

It is like something out of the Victorian photographic era; But if it works for him that's OK.