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 think upper & lower R, S, O & lower-case g & f are good to start with.
- R will give you a good start for what the serifs (if you are doing serifs) will look like for straight & slanted letters (eg, T, X, A, etc). A good beginning for B as well.
- S obviously a good start to B, while also showing you all the curves.
- O gives way to Q, C, G & sometimes D.
- g helps you see what the descender will look like while giving you a good start for most of the other letters with rounded bodies.
- f allows you to see the relationship between the main part of the letter & it's ascender.
After these, I would work on upper & lower M.
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'm by no means an expert, but I do enjoy fonts! Have fun with it & I hope this helps a bit!
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 nicest part is to start: sketching randomly, finding an idea and a general construction or characteristic; drawing the first letters and making the first words. As I said before I don’t have a specific letter which I usually start with, but there are some key glyphs which show the basic forms: n, b, o, v for instance for lowercase, A, H, O for uppercase.
I try in the begining not to concentrate too much on single letters but work on the whole alphabet and balance the single letters in relation to each other. That way I can set text very early on, and see how the typeface looks in small printed text—that’s usually very different from what you see on screen.
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.
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.
I recommend you start with /n, and keep a copy of the stem to use to for /i, and to extend to make /l, and then copy /l and combine with /n to get /h. The /n is very important because it gives you the x-height and the width and it gives you a main element to use for b/d/f/h/i/j/k/l/m/n/p/r/u. The /l and /h are the first letters to define the ascender height. The first letter for the capitals is /I, so you can define the capital height and use the letter to create B/D/E/F/H/J/K/L/M/N/P/R/T/U/Y. The capitals are not necessary to get a quick idea of what your typeface is going to look like, but I guess designing /I and /H won't be a problem because they're quick to do.
In conclusion, it's probably best to start with n/i/l/h/r and I/H. also, p for the decender.
The most commonly used letters in English are, in order, etaoin shrdlu. Having never designed a typeface, I would start with those letters purely because they are the most common.
My 2 cents. This is NOT to memorize, but to feel the flow.
Totally depends on the letter. For serif fonts and sans serif I would:
1) Start with an lowercase o. Simple, elegant, like a child starting to write.
2) d You can adapt the previous letter o with a vertical stroke to define the ascenders.
3) Suddently you now have a base for p, q, and b.
4) Take your b and now adapt it and transform it into an h, which can be the base of the n and r, probably the f.
5) You now have 9 letters to start thinking on what kind of type you need.
6) Go back to your o and modify it for a more complex shape, the c and the e
7) Go back to your ascendant and work with the i and l, and probably start with this l to construct your first capital letters. H, L, which is the base for E, which is the base for F.
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.
9) The point of this list is for you to see that one letter has relation to other letters. That is what makes a font-family.
10) I would leave at last the lowercase a, s and g. Probably the m and y. where you can have some freedom.
I'm surprised no one has mentioned hamburgefons, a word which was used in type samples of the 70s and 80s by some of the big foundries.
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.
There are other known variations like hamburgevons, hamburgefonstiv or hamburgefonts.
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.
Enjoy it :) Admittedly, I've never designed a typeface before, but I am a long-time designer and typographist (if that's a word), so these are just my two cents. Just develop a style and run with it!
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.
So I start with "etaoinu" letters, then proceed quite spontanously, e.g. "chslbdk"