I personally believe -- and work in this way -- that it's best to use both and just be able to judge where they are most effective. Ultimately, most panels don't hold the eye for a massively long time, and fine details are often lost unless it's a major panel designed to catch and hold the reader's attention. Because of this, I don't think it's necessary to put a huge amount of effort into non-focal points of less major panels; for maximum efficiency, it's always good to know which visuals matter and which don't matter as much. It's also best not to overcrowd panels with more detail than they can handle, which can risk making the intended focus disappear into the elaborate background. I've noticed that as a trend in some of the modern mainstream superhero titles, where some of the artists overdo it with background detail and as a result it's impossible to tell what's actually important or even going on.
Programs like Clip Studio Paint do allow for easy creation of your own hand-drawn textures and materials, as well as brushes that you can make from whatever images you want and set up as you like. I recommend it, and I use it myself; plenty of the brushes I have made in Clip Studio Paint, I have made to add ease and efficiency to my life! It's a more certain way to make textures and materials seem integrated when they're graphical in nature or patterns you want to blend: draw them yourself, very well, once, and make them into a material.
A small amount of detail, coupled with judicious use of screentone, can also make a huge difference. Even minimal accenting, combined with a bit of screentone for a feel of texture and color, makes things come alive on the page!