leather is a nice material, but it does require some maintenance from time to time to keep it that way. getting colder round here so its time to pull that jacket out of storage, and get it looking better cause it dried out

Step 1: Gather... Stuff

cant really call it tools or materials, the picture will tell you what you need but for those of you who read the entire instructable good on you and here's a list

work space: grab the old ironing board and cover it in garbage bags or other plastic so your wife/ mom doesn't yell at you when it gets stained
preservative: most leather conditioners will work, my suggestion is find something someone you trust likes or that's been around since the horse and buggy when this was in its prime my jacket is really dry so i'm gonna show you with Fiebing's Prime Neatsfoot Oil and then hit its with some Obenauf's Leather Oil for water proofing and protecting, if your leather is still in mostly good condition the latter should do just fine.
cotton: you'l need something to wipe it on with cotton balls will work but an old t-shirt is preferable, that said i'm using some WELL WASHED cloth baby diaper inserts they go longer between reloading's
gloves never hurt

Step 2: Get to Work

load up your cotton and start wiping on just like you'd iron a shirt, make sure you keep it even and get all the way to the corners and in the seams, be generous with it and don't be afraid to go back and re-do a section, it will darken some but it will lighten a little when you dry it

Step 3: Keep Going

you may have to modify the "wipe like ironing a shirt" a little bit due to the fact that a jacket is heaver than a shirt and the plastic is slippery but it will still work

Step 4: Dry

let it sit in a dry place at least overnight, depending on the type of conditioner used it may take up to a week (never tried it but iv'e heard that's what you have ti do for saddle soap)