I hate the term "glue" although I went through a period when I tried to glue everything. First, know that "glue" will not fix bad timing, poorly recorded, poorly EQ'd or bad sounding reverbs and delays on a track. Unfortunately, many people try "gluing" to dress a pig in jewels. In fact, I would not recommend any approach where you run the final tracks through a single stage of compression to make it sound better. Abandon this idea because it rarely works unless in some vibey, artsy, sort of effort in which the sound is meant to be trashed. It has its place in this case and Danny outlined how it should be used above.
My opinion is to stay away from compressors on the two buss. Just a limiter. Mastering generally adds a compressor across the mix and if there is any "glue" to be added, this would be the place for that. Get your mix sounding as close to your vision and smooth from a transient perspective, balanced from an EQ perspective and placed advantageously in the stereo field. Work on clarity, performance, the foundation of kick, bass, and snare along with the primary vocal so that these 4 have impact. Then work on tone matching the vocal to the primary rhythm instrument. If the mix is not sounding good at this point, a glue approach is just going to cloud the sound.
This does not preclude using parallel compression for vocals, drums or compressing individual tracks by the way. In a way, these should be used for fattening the sound or to focus in a specific frequency range. This is where the glue should happen anyway.