They make dedicated decapping dies and some guys use those. I don't have one and always size & decap at once.
Re: decap & tumble vs tumble & decap
It depends on how dirty your brass is. I like to wash my cases then Size & decap then tumble. But, I do it differently all the time. Last batch I skipped washing, sized & decapped and then washed in Lemishine. No tumbling.
