A beautiful warm-toned limited edition set of Tombows that you could use to draw citrus...or flowers...or bright orange kitties....anything you want, really.
I use mine to make to-do lists in my bullet journal, draw cartoon balloons in my pen pal letters, or spice up notes with polka dots. Think of all the possibilities.
We can never speak highly enough about Tombow Dual Brush pens. Use them in your sketchbooks, planners, letters, notes to yourself on your hand. Just use them.