Balloon walls are trendy for a reason
The endless variety of balloons available nowadays makes these DIY balloon walls the perfect craft to showcase all of them. Mix metallic or glittery helium types with round solid color pastel ones. Adding smiley face ones will make it even more fun. Of course, all your guests will be lining up to take pictures with this wall as a background.
Inflate the balloons and tie two of them together, then tie two duplets to make a set of four. Next, string the bunches onto some fishing line. Adapt this to any dimensions by just adding more rows. Alternate the colors and sizes to give some visual interest. Lastly, attach command hooks to the walls and hang the lines from those.