My friend Crystal hosts parties all the time, and though the food is always fantastic, the conversation lively, and the company excellent, the thing I find most endearing is that she buys fresh flowers for each and every party.
After the expense of food & drinks, it can be a tempting, nearly impossible challenge to spring for flowers, but she has a knack for creating something festive and welcoming no matter her current budget. The small bunch of mums divided into tiny bouquets and placed in tiny bottles (Pumpkin-Painting Party) creates an effect just as charming as lush purple-black lilies (Halloween) or multiple vases of poppies (Easter Margaritas!). One of my favorite displays was the result of sending her boyfriend out to find awesomely tacky flowers: nothing says "Now this is a party!" like big vases of red roses and baby's breath.
And if you're strapped for time, there's sure to be one nerdily on-time guest (me!) who will be happy to do the flower-arranging for you. Just supply scissors/clippers, various jars, bottle, or glasses, and a spot to work, and let them go to town. Whatever they come up with, flowers add a bit of party-magic that says to your guests, "I'm so, so happy you're here".
Image: Tess Wilson