The assembly of nano-building blocks into a desired architecture is a challenging subject in the current materials science. It is critical to direct the macroscopic-scale as well as molecular-scale arrangements of various functional nanomaterials. Particularly, the assembly of carbon nanomaterials (CNMs) (carbon nanotubes (CNTs) and graphene-based materials) into film, fiber, gel or micropatterned material may provide versatile opportunities for applications in nanoelectronics, energy devices, sensors, bioscaffolds, etc. Here I present a versatile and robust functionalization method for CNMs with polymers and facile directed-assembly method to produce cellular CNM scaffolds with tunable morphologies. CNMs were decorated with various polymers covalently or noncovalently through charge-charge interaction or surface-initiated atom transfer radical polymerization (ATRP). The self-organization of aqueous droplets upon a volatile solution, generally known as a ‘breath figure’, has been applied to the organic solution containing both polymer and CNMs as solutes and yielded macroporous polymer/CNM nanocomposite films. Upon the calcination of the polymer matrices, the resultant highly entangled CNM scaffolds maintained the macroporous morphology. In this work, their electric conductivity, field emitting property, and supercapacitor performance have been explored to elucidate potential applications for nanoelectronics and energy storage materials.