I've heard of lining the inside of the holster with wax paper. Is there any other way to break in a new leather holster? Or is it something even worth spending time doing? Thanks.

My Galco and Milt Sparks holsters did'nt seem like they needed breaking in.  They worked great right out of the box.

I've not heard of the wax paper trick.  Heard of a plasic bag/bread bag before.  I suppose it's all the same.

I was just about to ask the same question. I bought a Don Hume leather holster for my Kimber Ultra Carry and it is a little tight. I was wondering if there were any tricks to breaking it in without causing any serious wear to the finish of the pistol.

Re read above post.  

Most people I have spoken to about breaking in a new holster say generally the same thing:  "I put my pistol in a bread sack (keyword "put", not wrap), and put it in the holster overnight."  Tadaa! all broke in.  

Remember, your holster will loosen a bit naturally.  This aspect will give the holster/pistol a custom fit.  I would avoid using any type of leather soap or oil on the holster ever.  You want to maintain the tight grip on the pistol.