I said in the post about the sketchbox dice tool that you could make a "layout roll" to determine the way a town, village or hamlet looks, and what building are where. I should probably explain this a little more, since it's going to be important later on.
I've mentioned several times the idea of dividing a settlement into "conceptual quarters", based on the idea that a town has four parts: the area where merchants, nobles, or the ruling class lives; the area where the general crafts and support services are; the area devoted to whatever the town's main economic focus or other reason for being is; and the area for common laborers, peasants, and others of the lowest class live. The actual size or position of each quarter can vary, though, and for smaller settlements, the higher social classes might not exist. A village probably won't have a dedicated merchant's quarter or noble household; a hamlet won't have a specialty, but will instead focus on crops, hunting, fishing, or some other food-related labor.
On the sketchbox tool, the first three quarters are assigned to rings. Note that the order of the rings is linked to the size of the settlement, to make it easier to remember which label to ignore. To determine the rough arrangement of the quarters, you roll one or more six-sided dice (the kind with pips) on the sheet and check where they land. Dice that land in the Craft ring show where the craftsman's quarter is, relative to the common quarter. Dice that land in the next ring show where the "Focal" quarter lies (for example, the docks and shipyards for a port city, or the forges and smithies for a town devoted to metalcraft.) Dice that land in the third ring show where the noble or merchants quarter lies. Dice that land outside the outermost ring can represent an outcast or underclass area, if desired.
Each dot represents anything from one building to one neighborhood. The pattern of dots represents the arrangement of the buildings or other partitions within the quarter.
Commoners will always outnumber others. The total on the dice equals the total number of buildings or partitions in the common quarter.
If the settlement is a hamlet, you roll 1d6 and treat any Focal or Noble results as Craft. Each dot represents one building. There will always be at least one smithy and one mill (or other service related to the local economic activity.) There will probably only be one road, or at best an intersection.
If the settlement is a village, you roll 3d6 and treat any Noble results as Focal. Like a hamlet, there will always be a minimum of one smithy, one mill, and one tavern or inn, plus a market area. If more than one die lands in a ring, each die represents a different "district". Each dot represents a block; you can leave blocks undefined, rolling a d6 for the number and arrangement of buildings when the block is visited. There will be small roads between each block, larger roads between districts or quarters.
If the settlement is a town, you roll 5d6. In addition to the minimum locations for a village, there will always be at least one building for a noble or merchant family. Each dot represents a district; when needed, you can roll a d6 for the number of blocks in a district or the number of buildings in a block.
You have the option of rolling 1 die less for a small village or small town, or rolling 6 or more dice for cities. Cities will have more elaborate streets: use the letters of one short word per dot to define a neighborhood and roll a d6 when needed for buildings.