Several blogs offer instructions for making simplified papel picado (perforated paper) banners. These would be fun to whip up for a Cinco de Mayo shindig or birthday party. Find directions here:
Papel picado streamers by Studio DIY
Papel picado in purple and pink at Green Wedding Shoes
A downloadable template for papel picado from Happy Thought
Arrow-inspired garland by Lovely Indeed
Also see instructions for mini papel picado-inspired cupcake flags and straws. Consider succulents planted in cans for table decorations or party favors, too— like this or this. Little cacti are usually quite cheap at Home Depot.