The kick is possibly the most important instrument in lo-fi hip-hop as it provides a solid and steady base for the beat. If you’re not using sidechain compression already, you definitely should be. Add a compressor onto one or more of your rhythm and chord tracks, then select the side-chain and change the input to your kick track. This will turn down the volume of that track whenever the kick sounds, so the kick can punch through. Adjust to taste!
If your kick is lacking some ‘oomph’, try giving it a boost around 80-100Hz where the real meat and punch of the drum lives. Adding a small cut to other instruments with energy in this area such as the bass will help separate them out a little. Ideally, you don’t want much going on in the low end.
Kick eating up all your headroom? Using a saturation plugin is a handy way to fix that, as saturation is a smooth combination of compression and distortion. You should be able to shave 1 to 2 dBs off the peaks with a far more natural sound than using a compressor alone. Plugins such as FabFilter’s Saturn 2 actually have a dynamics knob for extra control over this.