What follows presumes that you want to do italic writing, the kind championed by the late Alfred Fairbank CBE.
Use a pencil, HB or B according to taste, and a toothy lined pad, the kind you can buy in bulk at Staples for example. The pencil can be a wooden grade-school kind, or a mechanical one. I use a 0.5mm mechanical.
Angle the pad comfortably (you'll probably alter that angle several times, so don't try to be religious about it. Design is an iterative process).
Start out writing lines full of connected lower-case 'a's. Don't pay too much attention to any one of them -- none of them are meant to be perfect because humans aren't perfect. Stay loose. Try, but not too hard, to make the second one similar in size and angle to the first one, and the third similar to the second, the fourth to the third and so on. Don't waste time trying to make the third similar to the first. If it's similar to the second that's good enough.
Once you have a good angle on the paper, and you can produce lines of similar 'a's pretty smoothly and without too much work --which could take you weeks or even months, so don't get discouraged: it's like zen or gongfu -it's foundational behavior, you're training your hand and eye-- shift to writing lines of aoaoaoaoaaooaaoo and so forth -a and o intermixed. Decide what kind of joins, if any, you want to use, which might be something else that takes a fair bit of experimenting. Make the bowls of the 'o's look similar to bowls of the 'a's. Then mix in 'c's the same way.
From aoac etc shift to ananan and then anonaononaoca and so forth (the mixing I show in this text is just meant to be exemplary, not the exact mix you should use), making the n as similar to the o, c, and a as the natural differences between the letters, and your natural human limitations, allow. Then add m to the mix. The m should look like the n, just one more hump. When you've got that down and can write any number of lines of mixed a n o m as you like, add w in the same way. The w is just an upside-down m, except for how it joins other letters, if you choose to join them consistently (you don't have to --experiment til you get a sense of what looks good and seems right).
Add g, which is an a whose stem dips down and can either come back up to join the next letter, or just be left cut off and the next letter started by itself. ggggggggagagagagaogomgna and so forth.
Add d, which is an a whose stem's starting point is higher than the a's - you don't change direction so soon, but it should look similar to the a apart from that. dddddddgdgdgdadadodmdn and so forth. Always mix in these new letters with the existing ones, trying gently to make them all look similar.
From there, add h, which is an n with a tall stem the same way a d is an a with a tall stem, an l which is an h without the n part. The b an p come next, which are sort of backwards d and g.
From there keep going, filling in the remaining letters to look similar to the ones you're already writing. Don't force the similarity -they should "agree" with the other letters, look related in other words.
When you've got them all in hand, start assembling words. When you can write lines of words, go buy a copy of Fairbank's A Handwriting Manual to pick up the capitals. Fairbank's book, because it gives examples from different people, should reassure you that what you're doing is completely within the tradition. You could also visit, and might even want to join, the Society for Italic Handwriting. Their website has nice examples.
Finally decide whether you really want to use a chisel pen to make your writing look more posh. Osmiroid of sainted memory were still making chisel-nib fountain pens when Fairbank wrote, but they went under some years ago because too few people were still interested any more. I don't know of another good maker (Pentalic wasn't, last time I checked).
So now that Osmiroid is gone, people like me have to go back to cutting our own goose and turkey quills, and grubbing around trying to find useful reeds for larger work. It's hard. It's also unnecessary for anything that's not going to be hung on a wall or bound into a book -- I get amazed comments from people even though I'm only using a pencil or a Sakura Micron pen. The key is the regularity. Unskilled writing with a fine chisel pen is still going to look like unskilled writing, while skilled writing will look fine even if the tool is a stick and you're writing in the mud.
Above all - have fun! Because if it feels like work, it won't look good.
APROPOS REED PENS: I found to my surprise this summer (2015) that garden/home-improvement shops (e.g. Home Depot in the US) have thin bamboo canes for tying up beanstalks and similar and those canes, after being soaked to make them pliable enough to cut, make very fine cane pens! Because of the diameter of the canes, they're best suited to monumental work, posters and similar.
Cut them in lengths to suit your hand, push out the pith in the middle (a bit of coat-hanger wire works well), and then cut them with the sharpest knife you have. I actually use a half-inch-wide wood chisel because my chisels can be ground sharper than any of my knives.
Once cut, split the tip a little bit with a fresh single-edge razor blade. Do it carefully, trying to center it as much as possible and long enough that it will channel the ink from your reservoir. The reservoir can be made out of a bit of a watch spring, if you have one, or half a bobby pin (watch spring is better). Or even stick a bit of cotton wool from a q-tip into the pith channel (that works less well than a bit of bobby pin or watch-spring). The basic idea is use something that will allow you to put in enough ink (use an eyedropper) to be useful and that won't instantly blob it back out!
If you don't have anything for a reservoir, dip the cane into the ink carefully.
In all cases, don't try to do finished work until you've figured out your individual pen's idiosyncrasies. They all have them and will take revenge on you if you don't stay within their limits.
