luckyslev, assuming it is in fact real leather, yes there sure are ways to speed up the softening... (i apologize in advance for the following novel)
- you can wear it and try to loosen up the fibers of the leather that way, but that does take quite a while
- you can condition or oil it with something like mink oil or neatsfoot oil. these can be found in better shoe stores usually.. neatsfoot oil can also be found in sporting goods stores (it is used to soften and condition baseball gloves)
- you can beat the crap out of it. crumple it up, put it inside a sock and beat it against the floor for a while. this is a bit extreme but if it is really stiff this might be your best bet.
oiling it will help a lot, if you oil it and then try to loosen up the fibers by stretching it out, and rubbing is back and forth across a hard corner. think of when you are trying to unfold a dollar bill for a vending machine, you use the corner of the machine to soften up the dollar- same method. i like to oil the leather and then use the top of a wooden or folding chair to rub it against. only rub the back against the hard corner, since you do not want to scuff up the front.
if you decide to oil it, try for a 100% pure neatsfoot oil, or a mink oil blend that has silicone and lanolin. avoid blends that have petroleum products as the petroleum can eat away at certain materials, like cotton.
these methods will work on real leather- chrome tanned, veg-tanned, and oil tanned leather. it might not be a good idea on bonded leather, which is what a lot of furniture is made of. bonded leather is technically leather in the same way that plywood is technically genuine wood. it's essentially leatherdust glued together with a coating on top and sometimes fabric or cardboard inside... you know those cheap belts you get that rip after a month or so? bonded leather. no bueno!
if it is vinyl... be careful with oiling it, as you do not really know how it will react. it's essentially plastic so depending on how it was made the oil could be very bad for it, or just sit on the surface and do nothing.
do not use oil from your kitchen. do not use mineral oil. do not! you need to use an oil that is produced for this purpose or you will have horrible results. plus you will stink. you can get good leather oils from tandy leather factory (there's a bunch across america, and you can buy online) if you are nervous about buying it elsewhere. if you do buy from tandy, i highly recommend fiebing's brand mink oil. it smells nice(sort of like nutmeg), where neatsfoot oil can sometimes smell like raw chicken.
apply the oil generously with wool or an old t-shirt and let it soak in overnight. then you can start trying to soften it. if it is too oily after you've made it less stiff, stuff it with newspaper or paper towels and change them out daily to absorb the excess oil. keep it in a warm, dry place during this process and it will help out a lot.
(i realize that this is a lot of info and i mostly typed up all of it up to educate everyone and answer as many questions as possible)