How to establish repeatable home position w/steppers?

Group,

On an open loop stepper system how do you establish a repeatable home
position? I'm thinking of a home position that will repeat to within
the resolution of the machine.

I can't see that normal, every day limit switches will do the job.
Dial indicators would be a pain, but would work provided they didn't
get bumped or readjusted. Some very old machines used a vernier dial
which was manually stepped to position.

So, what method are most of you using?

thanks,

Doug