There is a difference between designating a room from an existing built furniture such as bed, armor stand, table, or chair.
A player would normally use the q key and move the cursor over the furniture.
For example I q over the bed, at which point I press r, and begin designate a room.
DF automatically pre-selects a default room size of around 4x4 or 5x5 in size.
This pre-selects is reduces when there are walls and doors, so a bed in the middle of a 3x3 room, will pre-select a 4x4 area which includes the 3x3 room and the adjacent walls and door.
Pressing the plus or minus key increases the diameter of that room size with the bed at its center.
Pressing enter at that point makes that designation of the room's size.
If I recall correctly, the menu choices will be to resize the room, assign an owner, and free the room from current owner.
There is also designation for creating stock piles or zones.
P for stockpile goes to the stockpile menu.
Usually this is the time to set what kind of of stock pile it is.
There are default settings such as Food, Stone, Armor, etc.
There is also a c for custom, the t for settings which allows you to choose a combination of from what is stocked, to materials such wood or metal, and even quality of items such as finely crafted to artifact.
Move the cursor to where to place the stockpile.
Pressing enter starts the designation from that cursor position.
This cursor position is the anchor point of the square or rectangle, or even single tile.
Moving one right makes is 1x2, then moving one down makes it 2x2 with the anchor point from the upper left corner.
If instead from the anchor point, moving up one and left one, this will make the size 2x2 also, but the anchor point will be on the bottom right corner instead.
Pressing enter again commits to the size of that stock pile with the selected type of stockpile from either the defaults or custom settings.
And there is d designation for mining floors, up or down ramps, combinations of up/down stairs, channel. And then the plant gathering and cutting down trees. And also the smooth stone and carve fortification. They will all follow the anchor point, and resizing the x-y or width and height; and also the z-axis for the depth.
--
Anyway, one idea I use a Hotkey, by default the key F1 centers on the wagon. I am just not sure where the cursor is after pressing it.
This will give you a constant starting location.
I think dfhack has a function to get current cursor position, and move to cursor position.
That will help dictating (voice to text) and feed it to dfhack console perhaps?