We consider various aspects of effective gravitational theories, including supergravity, within the framework of the blackfold approach. The thesis is naturally split into three parts. In the first part of the thesis, we explore the blackfold approach and explain how it is possible to write down an effective theory for higher dimensional extended black holes in a uid/elastic perturbative derivative expansion. Moreover, we show that the approach is quite universal and can be extended to various supergravities. Finally, we consider a new generalization of the method, which allows us to treat (SUGRA) probe branes in uxed dilatonic backgrounds. In the second part, we construct and analyze thermal spinning giant gravitons in IIB/M-theory. The analysis employs the thermal brane probe method based on the blackfold approach. In addition to heating up the solution, and examining the effects from having a non-zero temperature, we also switch on new quantum numbers, namely internal spins along the directions of the wrapping sphere. We examine the effects of this new type of excitation and in particular analyze the physical quantities in various regimes, including that of small temperatures as well as low/high spin. As a byproduct of our analysis, we find a new stationary dipole-charged black hole solution on the AdS S backgrounds of type IIB/M-theory. We finally consider, via a double scaling extremal limit, a novel null-wave zero-temperature giant graviton exhibiting a BPS spectrum. Finally, in the third part of the thesis, we switch focus and consider long-wavelength perturbations of charged black branes. More specically, we consider hydrodynamic uctuations of the black p-brane solution of Einstein/Maxwell gravity in D = p + n + 3 dimensions. We extract the first order dissipative transport coecients from our perturbatively corrected solution, including the modified shear and bulk viscosities, and a new transport coecient associated with charge diffusion. Having obtained the transport coecients, we consider some of the usual hydrodynamic bounds and show that the shear viscosity to entropy bound is saturated, as expected. We also consider some of the proposed bounds for the bulk viscosity which are found to be violated in certain regimes of the charge. We finally compute the next-to-leading order dispersion relations for the effective uid. For small values of the charge, the speed of sound is found to be imaginary and the brane is therefore Gregory-Laamme unstable, as expected. For suciently large values of the charge density, the sound mode is found to be stable, however, in this regime the hydrodynamic mode associated with charge diffusion is found to be unstable. The electrically charged black brane is therefore found to be (classically) unstable for all values of the charge in agreement with thermodynamic arguments.