Gather balloons in your chosen colors and sizes
Get a balloon pump
Get balloon arch tape or fishing line
Get hooks, command strips, or a frame for support
Inflate the balloons to different sizes if desired
Tie off each balloon securely
Group balloons into pairs
Twist pairs together to make balloon clusters
Thread or attach the clusters to the arch tape or line
Alternate balloon sizes and colors for a fuller look
Fill gaps with smaller balloons
Secure the arch to your support structure
Adjust the shape and spacing as needed
Trim any excess tape or line
Check that all balloons are firmly attached