Its what I love to do. I dont need a reason. I pack a table and table cloth for the playground on Saturdays (and a bottle of wine - its for my nerves).
I'm sure you already know this. But just in case. Here is how to ALWAYS be prepared to give a pretty little party.
Fancy Nancy sets a great example, so I'd like to start here. Invest in these few things and keep them in your closet for spur of the moment occasions or your planned parties. You wont regret it.
Table Cloth A real one. Not your grandmothers heirloom. Something you wont mind washing again and again. Start at Target and go from there.
Cake Plate - I keep one on the counter in the kitchen even if its empty. Its pretty and I like to look at it. Your guests will too.
Plates and Cups - Real Ones. Not glass but some fancy acrylic (bpa free) tumblers will do.
Fancy Pastry of some sort - Cupcakes, cookies, scones, muffins...
Fresh Flowers - A few stems in a mason jar is a good start.
Name Tents - some white card stock, pretty paper and colored pencil/marker (or printer) are all you need.. Pop over to the Michaels, go to the clearance rack. Pick up your favorite and keep it in your drawer. You'll be glad you did. And if there are name tents you know there were actual
Invitations. Not Evites. I saved this until last, because I thought it might offend some people (and I'm not judging). Now I get it, we all live very busy lives. Who has the time to find, print, address, mail and track RSVPs for a real invite?! But it MUST BE DONE. Parties are personal. Thats why we have them. To eat, laugh, share, celebrate, make memories.. And the invite sets the tone. My suggestion is that if you cant send an actual invite, send a personal email to the effect of: "We are are having a little something for baby Sarah at our house; I hope you can come..." Its better. Electronic invitations are blasphemous. I'm not judging.. I'm just saying.
Check out my Pretty Play Dates - Essentials Pinterest Board where I've been pinning like a mad women with super cute inspiration.