The problems I had with the songs weren't in mastering, but in the mix. First, I think there should have been more atmosphere in both songs. More reverb, or maybe some little things like extra instruments with cool effects to fill up some space in the mix.
In the second song, I think the bass was pretty muddy, try rolling it off some by high-pass filtering 30-45 Hz and notch filtering 300-400 Hz to taste. Boosting the kick at 85hz a little and filtering below 50hz will let it work better with less clipping. Another option would be using sidechaining to help mix the kick and bass together.