Taking the trend a step down for the streets, we have subtle bits of neon to brighten up solid dark shades, like here at Gucci (left) and Lanvin (right).
To be more economical, instead of finding outfits with built in neons, accessorize the solid colors you already own with neons! Take here on the Cacharel (left) and DVF(right) runway- I LOVE how the bright belts adds extra personality to each outfit. The yellow belt makes the outfit instantly younger. And the fuschia belt gives the stark black dress a softer, more feminine and flirty touch.
So copy this look with this cheap skinny fuschia belt from UO and this not-quite-so-cheap yellow Elegantly Waisted cummerbund belt from Shop Bop. 
Even easier, forget the belts and just grab neon bright bags/shoes and pair it with neutral colored outfits, like here on the Marni (left) and Paul Smith Woman (right) runway.
For neon accessories, don't pick anything too fancy. The color IS the style. Go for something simple and classic, like these yellow ballet flats and even just flip flops from UO.
Or this simple yellow tote from UO. For something slightly trickier but definitely refreshing, try sprucing up your summer wardrobe with neon colored tights instead of the usual black ones, which frankly, becomes quick boring after all this time.
Something more subtle (and definitely more economical) that I'd probably go for are neon colored jewelry, like these necklace and bangles from Forever 21. They are the simplest and the most economical way to embrace this trend.
Then there are the neon colored skinny headbands and colored shades. I'm actually considering getting a pair of colored shades cause they look so cool. Incidentally I tried on a similar pair as the ones shown above at UO the other day and the fit is amazing. My only concern is that you'd have to make sure that the outfit you're wearing works with this particular colored shade- and hence my shades are either black or white. On the other hand.... it IS only $14.
The thing to be careful about with all this neon bright trend is that its a thin line between looking trendy and looking cheap. So try to be more subtle, pick one neon accessory and pair it with a classy looking outfit!
Photo Credits: www.elle.com, www.urbanoutfitters.com, www.forever21.com