I first mixed in different inks with small amounts of pearl clay for samples and then baked the sample chips and attached them to cards. I recommend doing this first as some of the inks can change their color drastically after mixed in with the clay or you might end up with a batch of clay in a color you might not like.
I wanted to be able to use my new clay colors for a mica shift to make the floral buttons so I measured out 3 parts of Kato pearl clay and 1 part Kato transluscent. I laid out my clay squares and put several drops of ink onto each square and spread the ink all over with a metal spatula so it would dry quicker.
Just for a measurement comparison, my clay squares were 2" and I used about 7 drops of ink per square.
I allowed the inks to dry completely before mixing in. I then created my flowers from the dyed clay. You can see how this mixture made an excellent mica shift.