For me, a pen that makes a bold line using gel ink is the way to go. A pen is a mundane thing, but if you write even a little now and then the mileage will add up. If you look at a pen as a “writing tool,” then having a good tool will make your writing experience noticeably better by being sort of effortless. All those short jots will accumulate.
The pen I currently use the most is the Pilot G-2. There’re other similar pens on the market and I’ve heard the Uni-ball Jetstream is the one to try next. But for me it’s the G-2 that’s smooth, inexpensive, and easy to find. The G-2 always makes a clean line and it’s a click pen so there’s no cap to lose. A G-2 glides along the paper as you write like you’re pushing a melon ball off a cutting board with a peeled banana, it’s slippery but with a bit of purchase.
Most of us don’t write by hand a lot these days and don’t give a pen much thought. But it’s a pleasure using a smooth pen when you do write.