You may have seen this kind of wood sign around Etsy or Pinterest. It goes for around $45. You can make it yourself for 1/3 the price with my help.
Buy plywood out of the lumber department in Lowes or Home Dept. It sells in 24x24 inch sheets. I ask them to cut it in half for me
$4.99 cost of wood.
Then you have 24x12. You can also have them cut this down again to make it 18x12 inches if you want.
Then spray paint and apply vinyl.
Ask for multiple colors or all the same color.