The luckiest day of the year is a good excuse to gather all of your favorite people in one place. A St. Patrick’s Day party should ripe with shamrocks, all things green, and some Celtic charm. Read on for our favorite DIY party decor ideas, and festive snacks. ShamROCK the Party! Personalized Invites From Treat We absolutely love Treat Cards! They have the most adorable customizable designs, and they’ll send the card directly to your recipient. What could be easier! Build the excitement for your Irish bash with personalized invites sent to all. Shamrock Flower Arrangement Use carnations and heart shaped floral foam to create this easy arrangement. Clover Patch Cake Topper Make a simple cake stand…