Whenever you have only 2 candidates in your cell, look for couples, triples and quads that go with that cell. When writing the candidates in your cells, write the 2 candidates in an order such that all of the 2 candidate results only show two options.
For example, if you have a triple of 13, 23 and 12, write the candidates in the cells as 13, 32, 21. Now it is clear to you that the only two options for this triple is 132 or 321.
As you start linking your couples, triples and quads together like this, you’ll make a chain that will run through the puzzle and allow you to easily see candidates to eliminate, or at least give you an easy method of filling in the entire chain once you solve any cell in the chain.