Because I chose to work almost exclusively with reclaimed materials, I found that it was impractical to do a complete design of the project first - I couldn't count on there being enough of a given component to complete the design. But I also didn't want to go grabbing materials willy-nilly, because I have a limited amount of storage space. In reality, the designing-sourcing cycle looked something like this:

Concept: I knew I wanted an outdoor kitchen made of several units, where the faces folded out to be tables, and I thought I wanted this to include a prep area, dish rack, sink, grill, smoker, turkey fryer, and chest cooler. That was enough to start.

Constraints: I already had certain materials (grill and leftover butcher block), so the units would have to be designed to incorporate those. In addition, I wanted the units to be able to be moved into my basement during the winter, so their width could not exceed that of the basement door (about 32").

In terms of their length, they'd need to approximate a small 6-person kitchen table (about 48"). The height of the units would need to be close to a standard countertop (about 36"), and the fold-out tables would need to be close to a standard table (about 29").

Using the concept and constraints, I started making rough designs of the project, eventually deciding that incorporating all of the things I thought I wanted would be WAY too much work. Instead, I chose to focus on the grill, turkey fryer, sink, and prep area, knowing that I could expand the units in the future.

With this design roughed-out, I started sourcing materials.