There are several aspect patterns that may be found in a birthchart and each is an amplification of the energies involved in their basic aspect sense.

The Grand Trine consists of three planets each making a trine (120 degrees) aspect to the others and thereby forming an equilateral triangle. All the planets fall within the same element, i.e. fire, earth, air or water. The chart below shows a Grand Trine in the Air element. This is an easy configuration in which the energy flows according to the element, without impediment.

The Grand Cross consists of four planets in square (90 degrees) aspect and two oppositions (180 degrees) usually within the same quality. The chart below shows a Grand Cross in the Cardinal quality. The energy here is stabilising and giving strength despite its usual adverse nature. 

The T-Square consists of an two planets in opposition (180 degrees) both in square (90 degrees) aspect to a third planet. This configuration usually involves signs of the same quality. The chart below shows a T-Square in the Cardinal quality. This can be a difficult configuration requiring hard work to overcome and subsequently benefit from.