In this invaluable book, graphic designer and design educator Karen Cheng explains the processes behind creating and designing type, one of the most important tools of graphic design. She addresses issues of structure, optical compensation, and legibility, with special emphasis given to the often-overlooked relationships between letters and shapes in font design.
Bio:
Karen Cheng is Professor of Visual Communication Design at the University of Washington in the Division of Design, School of Art, Art History and Design. Her book, Designing Type, was published by Yale University Press in 2006, and has been translated into German, French, Spanish, Chinese and Korean (see: designersreviewofbooks.com/2011/02/designing-type/).
Given many characters in a typeface build on others and even just a couple of characters can reveal a lot of the features of a given typeface, what characters are good to start with when designing a typeface?
I got interested in the question (I don't design type, I just design with it), asked around folks that do, and did some research. There doesn't seem to be a consensus -- every designer works with his/her own natural creative process, and many start with a sketched idea that could be any letter or a combination.
Here are some interviews from ilovetypography.com (an excellent resource, btw) that will give you an idea of the diversity of approach: Ludwig Ubele, Nikola Djurek and Alice Savoie. Ubele says, in particular:
The best typographic resource I know of on the web is typophile.com. There is a terrific "How To" section in the wiki, and you can branch out from there. This site will take you as deep as you want to go into typeface design.
My reasoning is when you work with these letters you get a feel for what the character spacing should be. Pay special attention to letters with large spaces next to letters that take up more space (L next to O, for example: LO) as well as the width of the letters (hence starting with, say O which takes up one space & then moving on to M, which could possibly take up 1.5 or 2 spaces, depending on how you design the typeface.
I disagree with joshmax's suggestion to start with R, S, O & lower-case g & f. I appreciate the reasoning, but the /S and /g are among the most difficult letters to design, so it's probably not a good idea to start with those to get a general feeling of the style and proportions of the typeface. In case of a serif typeface with a diagonal weight distribution the /O and /o are also deceivingly hard to design.
8) Have fun there, now the aditional feature, the diagonals... Start with the V and the A at the same time. Then play with the N... and a first risky choice... the capital M.
It was what I was taught to use in my two type design courses. The fact that it looks like a legible word even if it's not gives you a good feel of your font to be and letter space. It also contains most of the basic strokes you'll need to design your other letters.
ETA to build on my previous answer: I would recommended Designing Type by Karen Cheng. She advises to start setting the proportions and personality of your font by starting with a, e, g, n and o. Then you can work on a word often used by type designers "hamburgefontsiv". From this word you can build most of the other letters.
I really like to start with lowercase "a", "e", and "g". To me, these are the letter that vary the most, not only in style, but also general appearance. A's are either hooked at the top (Arial), or simply a bowl with a stem (Century Gothic). These can be identifying factors of your typeface, and give it a completely different feel.
In general though, I'm not sure the letter choice matters much, but rather the steepness and roundness of your curves (O's, D's, G's, etc.), the length of your stems, and the x-height of your letters. Once you have established these characteristics, the typeface should start to design itself, with you just assembling the pieces. If you place two fonts side-by-side, you'll understand what I mean regarding these characteristics. Unless you're going very stylized (Magik Marker, etc.), then these should be your primary focus, in my opinion.
When I design a font, I want to see how a whole text example is rendered. So I start with most frequent letters. Logically those cover more text as I proceed, or in other words, I can easier make example texts.
_frequency