To handle epoxy putty, you just have to mold it as if you are holding feather so that you won't make any dents or lumps here and there. Usually if putty or clay are soft. Tendency will cast your hand prints during the sculpting. Just have to plan and do it steadily.
What ink do you use to dye your resin? Cos I tried acrylic ink and I felt it was very cloudy, I have been using candy tone spray for mine. Cos they put the colour over nicely and also help me gloss up my resin, (other than the mirror backing that helps too)