What sort of products / designs? Big digital, I/Os,
mixed signal, RF, analog? Each has their own tools
and concerns.
Maybe people will offer you "interview questions" in
this thread.
It's been so long since I let anyone do layout for me,
I haven't thought about what I'd ask. But if I were
looking for that kind of help, for me it'd be about
craftsmanship, attention to detail and a "gut" idea of
what I'd want done, without me telling (not twice
anyway). Those kinds of layout dudes are product of
many years' on-the-job learning. If you are new to it
I suggest you make a "corrolary pitch", about things
you may be good at and why they relate to layout.
Like, most of the layout dudes who were any good at
my last job, wrenched up as a hobby and those who
never got dirty, were the ones I couldn't trust to do
it right without checking everything they did. Hand-
eye, visualization, debugging skills, all appropriate
attributes if not specific call-outs.