Pathing is the biggest FPS drain (including liquid pathing, which is easy to avoid). The biggest things you can do to save on creature pathing costs are:
0) Like everyone always says, make wide hallways.
1) Traffic designations, especially outdoors and in twisty maze-like areas. In mazes (like bedroom slums), set the bedrooms to low, and the arteries to high (main hallways) or normal (capillaries). Outdoors, set the whole outdoor region to low, then make directed corridors of normal or high traffic leading toward your fort's front gate, with a little bit of organic branching. The traffic designations outdoors should end up looking like a crayon drawing of a set of lungs when you're done. If you do a lot of stuff outdoors, this can easily quadruple your FPS singlehandedly.
2) Avoid long hauls in general. It's better to have a metaphorical (or literal) "bucket brigade" than it is to have a bunch of lone dwarves making the whole long trip. Think of the path as a semi-directional "plume" of searching. Plumes can be huge in open areas, and it's easier to plume out behind or to the side of you than into a twisty maze ahead. Whereas two or more small plumes start to more closely resemble a line and add up to less overall area.
To make a bucket brigade situation, you could for instance use overlapping burrows. For instance, outdoorsdwarves cut wood and move it to a 3x3 temporary stockpile right near your main door inside. Then indoorsdwarves with that area also in their burrow shuttle the wood to the larger wood stockpile somewhere deeper in the fortress. This leads to a small fraction of the total pathing that a single trip would take, even if the dwarves have to come from a bedroom or something to get there (if you set your bedroom traffic right), it still will be a huge savings.
Speaking of which
3) Burrows! Burrows burrows burrows. .... burrows. You don't need crazy complex burrows with each their own food and booze supply. You can just have the food and booze (and hospital, etc.) be in one burrow that everybody is in, and then add additional burrows for their industries, etc. Pretty easy actually.
4) NONE of the above things will help you though for invader pathing. To avoid FPS drag from goblins and such, you also want to avoid twisty mazelike trap areas. An example of a TERRIBLE trap for FPS is a long winding back and forth snake of cage traps. An example of a much more efficient FPS trap is a single straight line one tile wide path into your fort, with weapon traps, and then open space on either side with a pool of water or magma below (gobbos get cut up, or if they dodge, they fall off and drown). The pathing from outdoors into your fort through such a trap will be literally an order of magnitude or two faster than the winding hallway trap setup.
And of course have backup plans for your traps, so that you aren't forced to lock out seeking invaders, as they will constantly try to path in, grinding down FPS hugely as they search the entire map for an entrance. When invaders want to get in, you want to LET them get in and deal with them swiftly.
Having a twisty cage trap is fine as a backup for instance ("omigod there's a flying thing!), that normally is bridged off. That way, the infantry will hit your faster FPS trap first, but if they bring something you can't handle yet with efficint traps, at least you can just open the twisty trap and avoid havign them spam pathing outdoors forever.