I've had quite a lot of success so far this year propagating from soft and
semi-ripe cuttings but a couple of plants just seem very reluctant. I'm
about to try hardwood cuttings left over winter but before I use up my
limited stock material this way, does anyone know better ways to get them to
root:

Cotinus ( Smokebush). Apparently can be done with layering but even this
takes years. Is there anything quicker?

Photinia ( Red Robin).

Corylus Maxima ( a Filbert (sp?) )

Thanks,

Martin