My tendency is to combine a cool and (non-complimentary) warm color, e.g. blue and red, yellow and green. To push this, I decided to use a triad or split-complimentary color scheme. Instead of just using aqua and red, I added a dark yellow.
Supplies: Paper, Alphas, and Stickers: Simple Stories (Homespun); Ink: Tim Holtz Distress Ink (Scattered Straw, Fired Brick, Broken China), Studio Calico (Emerald City); Stencil: The Crafter's Workshop; Die: Lawn Fawn (circle stackables), Papertrey Ink; Punches: EK Success (1 3/8" circle), Stampin' Up! (scallop circle); Enamel Dots: Twine & Ink; Fiber: Recollections twine