8 DIY 21st Birthday Party Decoration Ideas to Delight the Guest of Honor

Between pulling off an intimidating new birthday cake recipe and finding the perfect gift (particularly gifts for teens) planning birthday parties are tough enough already. Why add even more stress to your plate when it comes to the decorations?

We're making your lives just a little bit easier with fun and cute DIY birthday decoration ideas for a 21st milestone birthday. Whether you're planning on throwing the event of the year, just want to impress a select group of friends and family at home, or are looking for even lower-key ideas for a two-person shindig, we've got you covered. 

These birthday party ideas for someone turning 21, run the gamut from being colorful and unique to subtle and sophisticated too. So, whether you're looking for ideas for your girl’s 21st big day or tips for hosting a memorable bash for a best friend, look no further! 

  1. DIY Table Runner

You don't have to opt for a store-bought table cloth year after year! Here, eye-catching gold details liven up a piece of pink fabric and work beautifully as a makeshift runner. Via Sugar and Cloth

 DIY 21st Birthday Party Decoration Ideas
  1. DIY Glam Champagne Glasses 

Looking for a fun way to personalize champagne glasses for a 21st milestone birthday party? These glam glasses make drinking champagne even more fabulous! Via Something Turquoise

 DIY 21st Birthday Party Decoration Ideas
  1. DIY Balloon Garland 

A balloon garland is a super easy way to make a big impact for any kind of adult birthday party! They’re actually incredibly simple to make which you’ll see with this tutorial. They make such an impact that they truly cut back on the rest of the decor needed for any type of celebration! Via Paisley and Sparrow

 DIY 21st Birthday Party Decoration Ideas
  1. Pink and Yellow Birthday Party Kit

This pink and yellow themed party in a box is just waiting to celebrate someone special!  We start with a fabulous birthday centerpiece that you can easily set-up in less than two minutes. Next, add birthday candles, napkins and a card with stand. 

Why not send as a gift, perfect for an at-home celebration or take on the go.

 DIY 21st Birthday Party Decoration Ideas
  1. DIY 3D 21 (or any number!)

Via This Splendid Shambles

 DIY 21st Birthday Party Decoration Ideas
  1. Free Printable 21st Birthday Invitation Templates

Create a beautiful 21st birthday invitation online without going outside of your budget, as in free; at no cost. Free 21st birthday invitations to edit, personalize, print with excellent image resolution, you can create and assemble your own birthday invitation online with personalized text. Via Birthday Invitations

 DIY 21st Birthday Party Decoration Ideas
  1. The Perfect DIY Mimosa Bar

What better way to celebrate your 21st birthday than with a bunch of bubbly booze!? Follow along with us as we guide you through the step-by-step process of planning the perfect mimosa bar and dish out all the day-of details you don’t want to miss. Via Modern Moh

 DIY 21st Birthday Party Decoration Ideas
  1. DIY Balloon Garland Cake Topper

This is a super quick and easy, customizable cake topper idea for your next 21st birthday party. The thought of creating this cute DIY Balloon Garland Cake Topper feels like even more work. But it’s surprisingly easy, I promise!

This tutorial will give you all the good DIY feelings because I’ve got lots of helpful tips for how to make a balloon garland DIY cake topper. 

Perhaps you are opting to go with a store-bought cake to save the stress. Or perhaps you’ve baked and frosted your own cake but don’t have much additional time for the decorating? Whatever the situation may be this tutorial will help you give that plain cake a quick and easy transformation into a bright and beautiful work of art. Via Sugar and Cloth

 DIY 21st Birthday Party Decoration Ideas


Remember that every great adult birthday party needs a theme, especially one as significant as a 21st milestone party! Take a look at our top 10 party themes for adults for some great ideas! If you don’t want to go for a full on theme, then you’ll at least need to choose a color scheme for your decorations and party supplies. Gold, silver and black are classic colors for a 21st birthday party. But if you want to be a bit different and still keep a classy vibe, then pink and yellow work great too.

 DIY 21st Birthday Party Decoration Ideas