Constraints Strategy
The Constraints Strategy involves manipulating the problem to work in your favor by adding additional constraints which do not affect the solution in any way or go against any of the constraints given by the problem itself. The most frequent example of this is giving a line segment a certain convenient value/length when trying to find the ratios of two other lengths.
This strategy has been used for a very long time, but the name was first coined by firebolt360.
Examples of problems that can use the constraints strategy: