This thesis presents experimental studies of single inertial particles in two main water fluid configurations: Quiescent Flow and Turbulent Flow. Furthermore, an experimental technique to modify the local gravity pull on magnetic particles, via the application of external magnetic fields, has been developed, validated, and applied to some cases on both fluid configurations. For the 1 mm spherical magnets here utilised, this method allows to reach any value of effective gravity between 0.5g and g. This allows to tune on demand, within a certain range, the Galileo number (and hence the settling regime) of particles in quiescent flow and to vary in the turbulent case their Rouse number independently of Stokes and/or Reynolds numbers, offering a novel approach for systematic explorations of particle/fluid interactions properties. In parallel, an experimental device that fulfils the constraints of the Dryden Drop Tower in Portland State University (USA) was designed to explore particle/turbulence interactions in micro-gravity (0-g) conditions. In particular, the Quiescent Flow studies can be split in two subcategories: Creeping Flow and Moderate Reynolds Number (around 200-450) Flow. In the Quiescent Creeping Flow case, the angular and translational dynamics of single slender metallic rods settling were measured to experimentally validate two widely used models that include fluid inertia: slender rod model and slender body theory. Whereas in the Moderate Reynolds case, the settling of spherical and cubic particles in otherwise quiescent fluids were measured in wide ranges of the parameters space (particle-to-fluid density ratio and Galileo number). In this way, numerical results predicting the different path regimes (rectilinear, oblique, oscillating, chaotic, etc.) in the parameters space were contrasted with the experimental results. Additionally, a new strategy using external magnetic fields on magnetised particles was developed to modify the effective gravitational pull on the spherical. The possibility to magnetically tune the effective Galileo number was demonstrated, hence allowing to explore on demand the different regions of the parameters space and therefore of particle settling regimes Finally, the Turbulent Flow studies can be split in two subcategories as well: Ground Experiments (eventually with magnetic control of the effective gravity) and Drop Tower Experiments. The same turbulent flow is utilised for both subcategories: it consists in a cylinder with water pumps at top and bottom, whose jets collide in the tank center to produce, to a good approximation, an homogeneous and isotropic turbulent flow with a well defined inertial range. In the Ground Case, the motion of single magnetic particles is tracked while the effective gravity pull is magnetically modified. The goal is to disentangle the role of Rouse and Stokes numbers on particle/turbulence interactions. Our experiments show in particular that the magnetic control of the effective gravity (hence of the Rouse number) impacts the hindering/increase of settling velocity in turbulent conditions compared to the quiescent fluid case. In parallel, a novel facility was constructed to investigate diluted suspensions of non-magnetic inertial particles (50 um glass, among others) in turbulence in micro-gravity in the Dryden Drop Tower. Due to the Covid19 pandemics, experimental campaigns in the drop tower could not be run during the thesis and are scheduled to start by the end of 2021.