Writing a Letter?...

... first, make your Quill.

After you have gotten you a good pen-knife well edg'd and smooth'd upon a hoane, and a good second quill, either of goose or raven, scraped with the backe of your knife, begin to make your pen thus:

1. First, holding your quill the right side upwards, cut off about the third part of it flat along the end.

2. And turning it on the backe side, cut off the very end of it asloape; which being done, it will be forte.

3. Then, holding it still on the backe, make a little cut in the very midst of the quill.

4. When you -have done so, take the end of your knife if it have a pegg, or else another quill, and make a slit up suddenly, even in the cut you gave before.

5. Which being done, turne your quill on the right side againe, and begin to cut a little thought above the slit, on the side which is next to your left hand, and so continue cutting by degrees, till you thinke you have sufficiently cut that side. But herein you must be very wary you cut not off too much of the slit; for then your pen will be too hard, and if you leave too much also, it will be too soft.

6. Then even against the place you baganne to cut the first side, cut the other likewise, till you have made them both of an equall thinnesse: and then trying it by lifting up the slit upon the nail of your thumbe, you shall see whether it be too soft or too hard: if either, bring it to a meane by adding more slit to it, if you see it bee too hard; or by taking some away, if you perceive it to be too soft.

7. Lastly, herein lies the difficulty, viz. in the nibbling of the pen, wherein I observe this rule, that placing it on the naile of my thumb, or middle finger I hold my knife somewhat sloaping, and cut the end of the nibbe, not quite off, but before my knife comes off, I turne him downe-right, and so cut the nibbe clean away, on both sides alike; contrary to that old rule, dextra pars penna, &c. Now if my pen be to write full, I cut off so much more of the nibbe; if small, so much less.

Martin Billingsley
The Pens Excellencie: Or, the Secretaries Delighte (1618)