I throw myself chaotically into botanical dye. Once I start I want to try everything. I begin with the easiest things I have around me that I have already read make good dye colour. My neighbour has huge avacado trees so I have a supply of stones and skins, it makes a lovely pink.
I am a bit late for pomegranate though I manage to find old skins on the floor under the pomegranate trees that have been half eaten by rats and birds. I soak the skins and get a beautiful russet orange. I am also a bit late for walnut hulls but again am able to gather enough to experiment a little and get a darkish sepia brown.
I am unsuccessful with Eucalyptus, I see the blue and red that seeps from the dried leaves that have sat too long on our outdoor ceramic sink but I am unable to get anything other than a dull brown.
Tumeric root makes a good yellow orange and acebuche wild olives a deep blue / purple. I try just about every leaf or flower in my garden with varying results. Once I have started I am curious about everything.