Use a paring knife to core a tomato: Insert tip next to stem, and then make a shallow cut all around; remove stem. To seed a tomato, cut in half lengthwise. Holding cut side down, gently squeeze to remove most of the seeds. Slicing a tomato is best done with a serrated or very sharp-bladed knife.
To clean radishes, place them in a bowl of cold water; swish around. Drain, and dry on paper towels. Before rinsing radishes with leafy tops, trim greens down to about 1 inch. Then with the tip of a sharp knife, scrape around the base of the greens, and pinch off the tiny root.