first it depends on your melody? is it a banging drop or is it just a breakdown melody?
if its a banging drop for eg, first you need a good super saw, EQ, compression, add some reverb, etc - sidechaining
for layering, some tips are
- the new sound to move it up/down an octave to cover different frequencies
- EQ is important if to cut some of the lows or highs of the conflicting sound
- adding white noise
- adding a pluck to a saw
- creating a group with bus reverb and delay and make adjustments to volume