Just a few ideas on some simple slip decoration inside some small bowls.
I used Cobalt slip and Nickel Slip Blue and Brown in colour.
The posibillities are endless and you don't need to be too fancy applying it.
Slip is easy to make simply add different amounts of whatever oxide you want to use to clay slip.
There is no formula to it as different glazes and clay bodies react differently to the strength of the slip.So If you make your own it's trial and error until you find the recipe that suits you.