reseller resource usage limit default

Hello. What's the way to setup a default reseller resource usage limit? I would like, i.e., that each new reseller has X GB of disk space, Y GB of bandwith, overselling allowed... but I can't find how to setup this for default. But for each new reseller, I need to go in WHM to "Edit Reseller Nameservers and privileges" and manually modify these limits... Does exist any way to setup this as default?!