Read the lyrics and raps of various artists who you respect. You can draw inspiration from the works of other rappers by learning different words, techniques and sentence structures they used to convey their message. Read lyrics and material from artists of various genres. Infusing a wide range of music styles into your writing shows range and creativity.
Jot down notes on your observations, impressions and perspective on what happened throughout your day. For example, if you have a conversation with someone you are attracted to, note the emotions you felt and his/her attire. When you sit down to write, refer to your notepad for inspiration. Rap is an art about taking personal experiences and making them connect with people.
Research the topics that you discuss in your raps. For example, if you write raps that focus on relationships, have a discussion with several couples to decide if your raps reflect the dynamic of their relationships. Incorporate facts and statistics into your raps if you discuss more serious matters. This shows that you know what you are rapping about.
Edit your raps once you finish writing them. Go over your lyrics a number of times, and ensure that they coincide with the intention you set out before writing anything down. Change any words or sentences that are not coherent. The lyrics in your raps should support the overall theme of the song.
Get feedback on your raps from honest friends and family. Since you're writing for an audience, it only makes sense to gain some insight from people before recording your rap. Look at the expressions on their faces while you rap the lyrics to gauge whether they are impressed or moved by your writing. Ask them for anything you can add or remove from the writing to enhance it.