For the last two forts, I've started to employ the tactic of periodic second hand clothing giveaway protocols, which drastically reduces the need to produce clothing items, thus helping FPS.
Clothing items will get used instead of being hoarded, and cluttering up cabinets.
What I do: Once or twice a year, I d-b-f over all my dwarves' owned cabinets to forbid all stored clothing in them.
I then wait a month for ownership to decay, and reclaim it all.
This will cause all XXitemsXX to be hauled to the refuse stockpile, where they'll decay, and all other clothing to be hauled to a stockpile, and then redistributed amongst your dwarves.
A dwarf will get a new item if
- it is available
- it is of better quality / condition than a currently worn item
So basically, you will see dwarves toss their oldest rags into their cabinets for the next giveaway round, and replace them with slightly better second handers, plus getting happy thoughts from putting on a new item if it's of decent quality.
The benefit of letting XXclothingXX decay over trading it away (at least for this release) is that decay in a refuse stockpile does not cause a masterwork loss event.
EDIT: basically, what this comes down to, is that instead of each dwarf owning 50 or more (and eternally growing) pieces of clothing after some time, you'll keep that number down to 12 plus some spares (I only give my dwarves a dress, cloak, shoes, cap and trousers, but I guess you could remove the cloak and still have all parts that can cause bad thoughts covered, bringing it down to 10 plus some spares). That's about 4000 less items bothering your FPS on a 100 dwarf population, more the older your fort gets.