Listened to a few, here's what I think.
Your drums are a bit too squashed i think. If you ease out on the compression, the single hits stand out much better and give your drum track a lot more groove when the transients slice through. First try to get on without any compressing or limiting, only use it as a last resort if some wild peaks need taming.
Melodies are good, definately your strong point, although I could spot some preset usage in there but that's no biggie, it only bothers other producers tbh. I especially liked the arpeggio in that Teardrops tune.
Your basses are really wide in the stereo field, you should check how the tune sounds when collapsed to mono. Try to use the bass as a rhythmic element too, hitting it on and off and playing with the relationship of the kick and the bass.
You got some really good ideas in regard to melodies and harmonies but in the technical side i think you still got some learning to do.
respect