Wood – this technique for matching cabinet veneers called

This isn't an answer, I just have a feeling I'll run up against the character limit for comments. What kind of wood do you have? How will it be finished? What is the basic construction style desired, face frame or Euro? What hinge hardware do you have or want? Is there backing? Solid wood or plywood? What wood working tools do you have available? Are you willing to acquire or rent what you need, within reason? Where will this be used, garage, bedroom, living room? Each implies a different quality of cabinetry. Is it wall mounted or floor standing? How much time are you willing to put in to this? What is you general skill level in woodworking?

You can see there's a lot of factors to consider for an ideal design. You don't really need to answer all of these, but the more you can communicate your expectations, the better an answer you will get. In reality you could end up just screwing together some basic butt joints and have a serviceable box, but it will not exude an aura of quality woodworking. Or it could be a literal work of art. Something in between probably, but where?

Hard to work without plans? How about hard to answer without information? :)

Hmm, those were harder to find than expected. It's extremely unlikely that you'll find an exact match (unless you can go back to the manufacturer of your cabinets), but here's a few possibilities.

Hettich: https://diy.hettich.com/en/products/connecting-fittings/carcase-and-cabinets-connectors.html

Blum: http://www.wwhardware.com/blum-surface-mount-rta-fittings-b040-2

Lee Valley: http://www.leevalley.com/en/hardware/page.aspx?p=40080&cat=3,41306,41319&ap=1 (Although these don't look like much, they're extremely solid and set with a satisfying thunk. They'll also come apart without wrecking anything.)