Tip: ms(mid,side or mono,stereo) processing is an amazing tool. It was originally intended for a way for mastering engineers to control certain instruments of the mix independently from the entire mix. However there's endless possibilities to how it can be use. Try using ms on your synth sounds. A lot of synths can take up a lot of space in the area a vocal sits. Using ms processing can help you create room in mono for the vocal while preserving the mid frequencies in the stereo.