For most projects, I have a square canvas that measures five-eighths of an inch. That's already small, but it gets smaller: even when you cut counters with a laser, there is still some slight variation. To protect against that, I have to keep the functional text and illustrations roughly 1.2 millimeters away from the margins.
What I'm left with, then, is a fraction over half an inch - about 0.53" to be more precise. The first thing that tiny little square needs to do is communicate. It'd be nice if it was also pretty - I want it to be pretty - but all the pretty in the world doesn't matter if it isn't functional. A player should be able to tell at a glance what the counter represents and what its capabilities are.
Wargames being wargames, these capabilities are often expressed numerically. Combat factors. Movement factors. Range. Armor. There are many counters for many games where these numbers are small and faint, making a magnifying glass a grognard's standard piece of kit. I prefer larger numbers, and generally reserve 0.17" of the usable canvas - roughly a third of it - for them. The fonts will vary, and so will the sizes, but it generally falls in the 14 to 18 point range. Big, bold numbers, easy to read.
This doesn't of course leave room for very many of them. Two factors are the norm, but we can squeeze in a third if attack-defense-movement is the order of the day. Rarely some superscripts will get into the act, indicating a modification or condition for a factor. Something like Lock N Load's World at War series, which can have as many as eleven factors and sub-factors on a single counter, that's out of the question for us. We wouldn't even have room left for the unit type illustration.
Like our numbers, I want those illustrations to be as large as possible. This is especially true of games where we've had custom illustrations done: we paid for that art, so we want to show it off as much as possible! But it even applies when we're playing the standards: X for infantry, a slash for horsies, bathtubs for tanks. We want that to take up as much of the canvas as possible, to be visible from a glance.
If the symbol's space is encroached upon by the numerical factors coming up from its southern border, it also needs to contend with any text bearing in on it from the north and at its flanks. If the counter represents Hiram G. Berry's brigade, then it ought to say BERRY up top. Here I need not only contend with the vertical axis, but the horizontal one: how many letters can I fit in a half-inch across, and still have them be legible? BERRY is an easy fit, but LONGSTREET is a little more challenging. I naturally don't want to be changing the size of the text from one counter to the next, so the first thing I need to do is determine what the longest name is, and whether or not it makes sense to abbreviate it.
So, we've got BERRY sorted, but suppose that his actions in the game are determined by the overriding structure in which he functions. Berry's Brigade falls under Philip Kearny's 3rd Division, which in turn falls under Samuel Heintzelman's III Corps. Well, then I'll need a "3" and a "III" somewhere on the counter, likely bearing in from the left, further constricting the space available for the unit icon.
Part of this little dance, of trying to squeeze every possible fraction of a millimeter of use out of the canvas, is determining what pieces of information really need to be there, and what pieces don't. When for example a game's units have consistent movement rates - say, all infantry move four and all cavalry move six - I don't necessarily need to put the movement factor on the counter.
Such was the case with Brave Little Belgium. The only thing I had to worry about there was the combat factor, which I represented with a die icon to emphasize the "roll to hit" nature of the combat. This gave the counters a clean, spartan look that I found appealing.
Then there are cases like Antony and Cleopatra. There, the movement rates were consistent, and so were the combat factors - each counter being worth a single strength point. There, I didn't need to use any factors at all, and could just rely on the unit illustrations to tell the story. That's what I prefer, but I don't always have that luxury; it depends on the game.
Working on counters for my own games are a different story of course, in that I design the game with the knowledge that I'll be doing the counters, and so can play to my strengths and my preferences. For both my Shot & Shell Battle Series and the Shields & Swords II games, the combat systems were designed so as to avoid putting numbers on the counters when at all possible. Game design decisions are made with graphic design decisions in mind.
This surprises people. I sometimes get questions along the line of, "If you designed a game that wouldn't work for Hollandspiele - too many bits, too large of a map, too many numbers on the counters, would you pitch it elsewhere?" The question is well-intended, but it’s ultimately a non-sequitur, because I always design with the end product in mind. There's that famous line from Frost about free verse being like tennis without the net, and it's a little like that. I don't see these things as limitations constraining me - I don't feel constricted at all - but as the meter and the rhyme scheme - as the format.
Which includes, of course, fitting everything I need on a square canvas that measures five-eighths of an inch.