1) Plan early if you can & pick a theme that you can run with. In addition to holidays, throw parties for any theme: movie night, mystery dinner, Mardi Gras, Kentucky Derby, Nascar, Cinco De Mayo, sports games...be as creative & fun as you like.
2) Decide on your guest list & give your guests preferably between 2-3 weeks of notice.
3) Start thinking about decor to go with your theme.
4) Come up with a specialty cocktail for the party that goes with the theme. Having that special drink of the night can always add to the fun!
5) Make a To Do list for the party. You will be surprised at how many things can get done in advance.
6) Plan the food & drink. I try to serve a mixture of nibbles to put out on coffee tables, some cold food items and some hot. You don't want all hot appetizers, as there is only so much room in the oven an hour before your party. You also don't have to make everything. Perhaps make some of your dishes & order the rest from local businesses that you want to support. Some guests may also offer to bring a dish to the party. Either give them a suggestion that goes with the theme or you can do a pure pot luck where everyone contributes anything they want.
7) Probably the most important tip: just have fun! Life is meant to be lived. Don't stress about the mess in the house with everyone there or whether everything is perfect. The most important thing is that quality time or wonderful memory that you are creating with family and/or friends. Create memories!