Ideal Gas Law related pressure, volume, and temperature through the following equation:
PV = nRT where the variables equal the following:
P = pressure
V = volume
n = number of molecules of the gas
R = constant
T = temperature
If we want to know how to increase pressure, we can solve for P in the equation.
P = nRT/V
Therefore, in order to increase pressure, P, we need to increase the number of molecules of the gas, n, increase the temperature of the gas, T, or decrease the volume of the system, V.