Choose a venue (Home is usually best!)
Choose a date and time (try to pick a between-meal time)
Make guest list and plan for digital invitation
Create menu and plan for custom cake (cupcakes, ice cream, etc)
Take inventory of supplies you already have for the party. (Tablecloth, serving dishes, pitchers, etc.)
Make list before heading to the dollar store for themed decor items
Do as much as possible the day before the party so you can enjoy the day!