whether they're for the drop or breakdown, using one synth over simple chords. Even if you end up not using chords on the drop (i.e. a big kick with one note) I think it's still much easier to be inspired when writing those melodies to chords. My collab "Burn" with DallasK was done this way.
2) Learn at least one scale really well. For instance, I'm most comfortable in F minor. I know what notes are used in other scales, but because I know F minor so well I can hear in my head which notes sound good together it saves a lot of time.
You should also learn variations of the scale for more interesting melodies. For instance, the F harmonic minor scale adds the note E. Thus, the C major chord is available and it builds tension extremely well, especially into an F minor chord.
Of course, not all of my songs are in F minor. I transpose the melodies after I write them. Ableton has a useful MIDI effect called pitch that you can apply to any synth and it will do this for you.
3) I recommend adding pitch bend, portamento, vibrato and velocity variations to your melodies. They help break the monotony and add a lot of feeling. You can hear pitch bending on both the lead synths and the bass in my track Secrets with Tiesto. Also, be conscious of the length of all of your notes and how that affects the rhythm you create. This can be very important.