What two things increase the gravitational pull between two objects?

In order to increase the gravitational forces between two objects,

you have exactly two choices:

- - Increase the product of the two masses.

- - Decrease the distance between their centers of mass.

Two things that increase the gravitational pull between two objects are decreasing the distance between the objects and increasing the mass of the objects. the force due to gravity is F = GMm / (r^2) where G is the gravitational constant, M and m are the masses of the two objects, and r is the distance between them.