The paper outlines the optimization of plasmonic nanostructures in order to improve their sensing properties such as their sensitivity and their ease of manipulation. The key point in this study is the optimization of the localized surface plasmon resonance (LSPR) properties essential to the sensor characteristics, and more especially for surface-enhanced Raman scattering (SERS). Two aspects were considered in order to optimize the sensing performance: apolar plasmonic nanostructures for non polarization dependent detection and improvements of SERS sensitivity by using a molecular adhesion layer between gold nanostructures and glass. Both issues could be generalized to all plasmon-resonance-based sensing applications.