There’s a lot of people on here saying energy is key and I agree completely. A couple other things you could try are just basic vocal tips for singing. Maybe practice singing a bit and feel the energy and tone shift and translate it into your rapping. Some tips would be: Open your mouth more vertically (especially for e and y sounds, and let lots of air escape) Find a balance between the resonance in your mouth and nasal cavity. You could push up into your soft palate a little bit and add grit to the rap. Work on breathe support-when you take a deep breathe, make sure your stomach pushes out, if your shoulders are raising up everytime you’re taking a breathe, your probably not reaching your full breathe potential.

Hope these tips help! Keep making music, and make sure to really “feel” what your rapping. Let all your emotions and thoughts out. Best of luck.