The main easy fixes are the following.
Bass
1. Add in a sub bass (literally a sine wave)
2. Saturate your current bass and make sure it does not pan or use an imager
3. Process them together via another amp if you like
Melodic group options
1. Overall go louder and splash around with reverb
2. Easier solution is the overall reverb and parallel compression (go louder)
Drums
Kick needs a good once over (Pultec EQ)