Soft pencils and broad fountain pen nibs
When I first got around to buying a box of Blackwings (after having it on my “stuff to get” list for two years, and I started using them it hit me how similar it was to using a broad fountain pen. They are both messy, put down a very satisfying line and you have to refill / sharpen it all the time. Or at least a lot compared to their finer / harder bothers.
Like I said, they are both high maintenance and very messy. If you use a broad nib you’ll end up with ink all over your hands, and if you use a broad pencil you’ll end up with graphite all over your hands.
I very soon realised that a little bit harder pencils are the thing for me. Because unlike fountain pens, there are much less you can do about it, except carrying a lot of pencils. If you like broad fountain pen nibs you can just get a huge piston filler and ink capacity isn’t a huge problem. Pencils on the other hand requires sharpening. And there is a limit to how many you can carry. How messy they are is also a part of it for me. A fountain pen is messy, but after a few seconds the ink is dry while graphite will smear the same if you drag your hand over for the first time after a minute or ten.
Even though I use Broad fountain pens, I have landed on #2 / HB pencils as “my thing”. Smooth enough for it to not annoy me, while at the same time hard enough to not look like a crazy person while I write.