Sukkos (or Sukkot, depending on where you're from) is not one of Judaism's most well-known holidays. It doesn't even have a single English name; it is known variably as the Festival of Booths and Feast of Tabernacles, among other appellations. Coming on the heels of the very well-known High Holidays of Rosh Hashana and Yom Kippur, it is given short shrift by the general public, but is very much a beloved and important holiday for those in the know. (Here's a handy guide from Oorah about the holiday, in case you want to get in the know.)
One of the fun and exciting parts of preparing for Sukkos is decorating the little hut that is the sukkah. Want to make your own decorations but don't know where to start? Here are some links to creative ideas; use them as is or as a springboard to get your original ideas flowing:
A quick Pinterest search brings up many sukkah decoration boards. Here's one, from Oorah.
From blogger Mara Strom: http://www.amotherinisrael.com/guest-post-easy-inspiring-sukkah-decorations/
And from Sharon, of Fashion-isha, some really different ideas.
Then of course, you can always go the easy route and buy your sukkah decorations. It's not really cheating. Just don't tell anyone! Greenfield Judaica has a nice selection.
Of course, all you need for your sukkah to be kosher is two and a half walls and some schach, but the nicer your sukkah, the happier you'll be to live in it for eight days (seven, if you live in Israel.) So go ahead and get decorating!