I use mostly Photoshop CS5 now, from back when you could buy a cheap(ish) student version. Even though Photoshop isn't really designed for comics, I've built up a lot of tools and templates and such over time to make the process more streamlined, including have a document that's premade at the page dimensions I want, along with folders nested in the way I like for each panel to be its own folder, a layer already made for the frame and ready to be masked, and even dialogue bubbles in a dialogue folder. (For perspective for backgrounds, I downloaded some free brushes to use as guides, though Photoshop has no native ruler tools like Clip Studio, so it's still vertical/horizontal lines or else hand-drawn.)
I did use MangaStudio EX4 (pretty much same program as Clip Studio I think, just a different name) for inking for a long while to see how I liked it, using the pen stabilization tools and also the rulers, but after trying that for several scenes of comic, but in the end I decided I just preferred to freehand without stabilization, and I was just too used to raster based programs that I wasn't using the tools that make vectors an advantage. And I just liked the more organic look of the lines in Photoshop, even if they were a little more scratchy close up.
I do do a lot of sketches in sketchbooks and scan them in insert into storyboarded pages (which these days I usually sketch directly in Photoshop), but most everything else is done on the computer.