Lattice

Reshape the whole form with a few controls.

Use a lattice cage to make broad changes to a modeled object. Move cage controls to adjust its proportions and silhouette without selecting individual surface vertices.

Try it in HardCuts
Lattice in the HardCuts viewport
Lattice in HardCuts.

Build and adjust the control cage

Select the object and choose Lattice Tool under Tools > Deform. Set the X, Y and Z cage divisions in the Actions Panel. Begin with a small number of divisions for overall proportion changes. Select cage controls and move them to reshape the enclosed object.

Review the surface before applying

Orbit the model between adjustments and check the silhouette and thin regions. More divisions provide additional controls when the shape needs a localized change. Apply commits the result, Reset starts over and Cancel leaves the edit. Review the working voxel resolution if the surface is too coarse for the intended deformation.

Good to know

Should I start with many cage divisions?

Start with fewer divisions for broad changes. Increase the control count when the shape needs it; a dense cage is not necessary for a simple proportion adjustment.