Short answer : Whatever works 😉
Now I tend to rely on open source software(s) so GIMP, Krita, Paint.net, Inkscape, LibreOffice or OpenOffice.org Draw, Scribus… etc… If it gets the job done, that’s fine with me. ^_^
A while ago, Sade explained that some version of Photoshop was available for free. You should be able to retrieve her post from the forum’s archive if you’re interested. So there’s that, too.