Hi:
I found some great putty applicators in a craft store used for cake decorating (they sell models too). They're thin flexible white plastic and come in a variety of shapes. There's chisel ends, pointed ends and a bunch of different curved and rounded ends. If you don't find a shape that you need, then get a couple of extras of the same shape and carve them to suit. You can get them in packages of 3 or 4 as a starter kit or buy them individually. I picked up a dozen different shapes and spent just over $10 for the lot of them.

Tamiya released a set of Paint Stirrer's, I think they came in set's of two. They also work pretty well when using putty

Cougar