When you are planning a party there are a lot of things you need to take care of well for the starters:

Occasion

Theme or a Casual Party

Guests(whom you want to invite) 

Food, Snacks & Drinks you want to serve at your party

Decorations 

Glow & Light Products to make your Party Fun

Yes they can firstly they are cheap and widely available and party planner always have the option to choose from different sizes, colors & shapes thousands of different types of led glow light up items are available online.