Between flanger, phaser, and chorus. I know some people swear by putting phaser or flanger in front of their dirt. But for me, with an MXR Micro Flanger, it was just too subtle in front of my dirt pedals. I just obtained an MXR Phase 95, and currently have after dirt with my flanger. They’re both going into front of amp, which I do have on the dirty channel, but with low gain. And my chorus is in the loop along with delay and tremolo.
So my chorus and flange come from the deco, so I can’t run them simultaneously, besides doing the auto flange for small passages, which sounds great btw.
Usually if I’ve got phaser going, it’s alone, or with some very very subtle chorus as a sweetener/thickener.