We demonstrate that a crosslinked polymer network can permanently mold spatial soliton waveguides into nematic liquid crystals for the confinements of optical signals, paving the way towards a novel bottom-up technology for guided-wave photonics with beam-shaped circuits. Moreover, we show that stabilization through polymerization is effective in quenching the trajectory fluctuations of such spatial solitons -nematicons-, allowing also their real-time use for all-optical signal processing.