Hmm, i'm no expert, but maybe try extending ur use of punctation and caps, cos it'll make it clearer to the reader how it wud sound if u were spittin in real life. Use caps to show what words will be emphasised and volume. I mean fuck you, sounds tame compared to FUCK YOU!!! n its more realistic, no1 jus says fuck you in a normal voice. Haha, pretty shite example but u kno what I mean. If u were tryin 2 make it sound more personal, or if say it was retaliative (after they'd said it 2 u) u cud make it fuck YOU!!! dunno, jus sum ideas