Ok not really scientific but I am doing some dye experimentation with black beans and some white cotton lace that I got at a yard sale. Since I am bored and on the subject I thought I would share some things I have learned about dying with plant and food dyestuffs.
Rule 1. GLOVES! seriously some dyes are pretty darn permanent even to skin and modern society is not exactly accepting of people wandering around with green or orange hands. Also newspaper and some wax paper to protect your counters. You make think the new colors are pretty but your landlords/roommates/significant others may disagree.
Rule 2. LABEL! if you are doing a dye that needs to set in the fridge or outside then label it because dyes can be pretty stinky or gross if you open them. (Also they may somewhat resemble juice and just throwing them in the fridge in an unmarked waterbottle is cruel.... apparently)
3. Research. see if someone else has used this dyestuff and what tips they may have. I found a knitter online who had used black beans as a dye and instead of boiling them she just used the leftover water from soaking the beans soak them in a tupperware. I am using a clear(ish) waterbottle so I can watch the results.
4. Experiment! go ahead get a labcoat and goggles (good plan if you use a strong mordant like spirits, vinegar or alum) and cackle maniacally
5. Have fun and make sure to document your progress to show the rest of the class ;)