Short list for 4 to the floor:
1. You need low end (lower than 60hz) and tune it
2. Make sure it's not too saturated to begin with (replace it)
3. Keep your low end mono
4. Play with your ADSR setting to make the kick short and tight
5. Cut boxiness out
6. Only saturate the top end
7. Just use a good kick to begin with :D