If you're looking for more chic and sophisticated 30th birthday invitations, check out this site. Note that they have a lot of great illustrated invitations, such as the ones below, but they are not listed under the milestone birthday section on their website—so be sure to check out their general party invitations too and then just customize the text accordingly.

Laser cutting can add some really intricate designs, cut outs, and patterns to printed invitations, giving them a delicate, sophisticated, and expensive look and feel. They're often used for weddings, but I think they're a great way to make 30th birthday invitations just that little bit more special. Browse the full range here or click on any of the images below to view that design.

Another fun and unsual idea for party invitations are these anaglyph 3D ones that come with old-school 3D glasses for guests to decipher the details. The examples below are from wedding invitations and save the dates, but all can be customized for a 30th birthday. Of the best 3D photo invitations I've found, option 1 below, are available here or option 2 below is available here (Note: option 2 doesn't come with 3D glasses but you can pick them up here). For 3D invitations without photos, the best I've found are available here (option 3 below), here (not pictured), or here (not pictured).

These scannable stickers are a great way to add a personalized voice or video message to any party invitation. Just record a video or voice message on your phone, link it to one of the QR code stickers, attach it to your invitation, then when the recipient receives it they scan the sticker with their phone to play back the personalized message. The stickers come in packs of 100 so, in addition to adding to invitations, you can use them in many other ways, for example adding grandpa's voice to a storybook or leaving instructions around the house for guests—such as how to use the TV remote. Check them out here.

Another way to make your 30th birthday invitations more personal is to record it in your own voice with these stick-on sound tags. Available as 10, 120, or 200 second sounds tags, you simply record your message, peel off the adhesive backing, and attach it to your printed invitation. Because of the unsightly wiring involved, the recordable sound tags come encased in slim matchbook style wrapping. You can choose between pre-designed ones, that say things like "congratulations" or "birthday wishes" (below), or blank black or white ones (below). Check them out here. If it were me, I'd go for the blank black or white option, then have some custom sticky labels printed (only $3.15 for sheet of 30), like the ones below available here, with some brief instructions—such as "Amy's 30th Birthday, press for details". They also make light-activated sound tags that start playing automatically when taken out of an envelope / gift box, so you could do away with a printed invitations altogether and just add a custom sticky label with instructions and send them out in a gift box filled with shredded tissue paper like the ones below. See here for affordable gift box options.

Another trick used by professional party planners is to incorporate a three dimensional object into the design of our invitations—which instantly makes people sit up and take notice. People just love to receive unusual invitations—and often they're not expecting a 3D object to arrive in the mail so it really captures their imagination and gets them excited about the party. Below are some great examples from professional events, including a couple by my own company Left Field Productions.

Update: a lot of people have asked where to buy ornate keys like in the example below, so I'm including a link to these here. It's also a good place to start for other 3D objects you might want to use as your invitations. Alternatively, check out this site here for inexpensive novelties and party favors—such as disposable sunglassess, foam baseballs, rubber duckies etc—that you can use depending on your party theme / occasion.

If you're going to use an object as your 30th birthday invitation, I would suggest keeping the printed card part (with the details on) simple. All you really need to do is have the party details printed onto a custom tag (like in the London Dry Gin key and rubber snake examples above), which you can pick up here for around 35 cents each, tie it on with ribbon or string, and mail them out in small gifts boxes. This site here has a great range of gift and shipping boxes, many of which are sold in packs of 25 making them only 45 cents each. Alternatively, if you want to make the tags a little more special you can also have them made out of wood for only $2 each, check them out here, or transparent acrylic for around $5 each, check them out there.

These personalized printable candy bar wrappers are a great way to combine a 3D object invitation with the "In the style of..." approach to invitation design. This Hershey Bar wrapper, below, would make an unusual birthday party invitation. There are lots of of custom candy bar wrappers available online, but most are intended as favors so they don't have enough space to communicate all the party details in order for them to be used as invitations. This design is different in that nutrition information box on the reverse has been adapted to accomodate all the party details. Check it out here.

Alternatively, the same designer has other custom candy bar printable wrappers available, such as Snickers, Rolo, Nestle Crunch, and Reeses (click brand name to go to that option). While these haven't been designed specifically to be used as invitations, the designer offers a "custom modify" upgrade option for only $5 available here, so she can add additional text on the reverse to communicate all the party details.

For something really unusual, how about sending a cake postcard as your 30th birthday invitation?! These hand-made almost life-like cake slices have a card attached one side and can be sent through the mail as they are—just apply postage! Check them out here. Update: There are several suppliers offering these, but my personal favourite is this supplier here. Not only are her cakes the most realistic looking, she doesn't use a basic looking postcard (like some of the ones below) and offers to hand-write the cards and pop them in the mail for you.

Another way to make your invitations stand out is to go for a fun retro design. The two best site for retro-style invitations are this site here, and also this one here.

Another fun way to customize birthday invitations is to have a custom portrait or cartoon made of the birthday boy or girl. There are many different styles of portaits available here, or click on any of the images below to see more of those particular styles. Some of these are intended as wedding invitations and so feature couples and families, but most of the designers will happily customize these if you're looking to feature just one person.

These custom crossword puzzle invitations are often used for weddings and save the dates, but there's no reason why they can't be used for a 30th birthday invitation. The clues and answers you provide are a great way to really make the invitation personal (and test how well the recipient knows the birthday honoree!). Check out a range of options here, or I quite like the photo ones shown below, available here. Don't be put off by the cheesy stock photos used in the examples below, with the right photo I think these will look great.

I'm including these fantastic metal invitations just because they're so unique, but unfortunately they require a minimum order of 50 which might make them too expensive for a lot of people—unless you have a healthy budget. Check them out here.