An earth-boring tool comprises a body, a plurality of blades, and cutting elements. The body has a face at a leading end thereof and comprises a cone region, a nose region, a flank region, a shoulder region, and a gage region. The plurality of blades extends longitudinally and radially over the face. The cutting elements are disposed within the shoulder region of the body on different blades of the plurality of blades than one another, a first of the cutting elements exhibiting a different size than a second of the cutting elements. A method of forming an earth-boring tool and a method of forming a borehole in a subterranean formation are also described.