I found that my handwriting was most legible (least illegible!) when I used a 1mm fibre-tip 'calligraphy' pen. Similar effect to a fountain or nib pen in that it gave some shape, but without the splatter and ink variation (and drying up) I've always had with ink pens (I'm very inconsistent with pressure, my hands move too much). But I haven't seen those pens for several years.