When should an effect be used on a return track? What should the wet/dry mix be set to?
Certain effects make sense to be used on sends. Commonly, a send would be used for effects in which you still want to hear the dry signal. This makes sense because when a send is turned up, the dry track volume is not attenuated.
When using a reverb or delay on a return track, it usually makes sense to have the wet/dry mix set to 100% wet. For example, if you’re adding reverb to a snare, place the reverb on a return track and set it to 100% wet. Use the send amount on the snare track to determine how much reverb you want to layer over the top. If the reverb had some dry signal as well, when you turn up the send on any given track, the dry track volume will increase.