We study both, theoretically and experimentally the light-to-surface plasmon polariton (SPP) and SPP-to-SPP scattering using the Green's function method and leakage radiation microscopy. The scattering structures are fabricated by nonlinear lithography and laser induced transfer (LIT). SPPs are exited on dot- and ridge-like surface structures. We demonstrate symmetric or asymmetric excitation of SPP beams and show that the SPP excitation efficiency strongly depends on the component of the excitation field perpendicular to the metal surface. By adjusting the angle of the incident beam to the maximum of the total electric field component perpendicular to the metal surface, the scattering efficiency of light on a single nanoparticle into SPPs can be increased by a factor of 200. The SPP beams allow studying scattering properties of perfectly spherical gold particles with diameters between 200 nm and 1600 nm fabricated by LIT of liquid gold droplets. For these diameters, the description of scattering of electromagnetic waves with optical frequencies has to take into account higher-order terms. Leakage radiation microscopy provides the unique possibility to observe scattering features attributed to magnetic dipole and electric quadrupole contributions in the 2D scattering patterns of SPPs. The results are supported by numerical modelling using the Green's tensor approach.