One of my childhood best friends became a stylist and we were roommates in our late teens/early 20s. He showed me how to use the tools that don't come with the drugstore kits, as well as how to mix the color. I have a designated "hair color towel", a little bowl with a handle, a long handled paintbrush-looking thingy, gloves, and vaseline for my hairline. The key is painting on the color, not squirting it on like the instructions on the box say to do. You can get coloring supplies super cheap at Sally Beauty supply and even my own stylist (who cuts my hair) says that I do a great job! As for the sink, should you get a drop or smear, wiping away with a wet paper towel right away does the trick, even on porcelain. Just don't let it sit!