Try mixing up the beats that you freestyle to. There’s instrumentals in so many different genres, so don’t limit yourself to your favourite style of hip-hop. Practice with different tempos, different rhythms, different instrumentation and different vibes. There’s lots of club music that’s very suitable to start with: house, breakbeats, electro, dubstep, old funk, soul, R&B, rock, jazz, Afrobeat, reggae, soca, reggaeton, moombaton, etc., etc., etc. Try music you don’t normally listen to. Include country, folk, bluegrass, pop, classical, and other genres from Africa, South America and Asia — even mediation records, talk radio and noise. Every genre can teach you something new. Don’t freestyle to them all in the same way — let them influence you to try a new style. You’ll be surprised by what you come up with when you listen to beats outside your regular playlist. Everyone has tracks they prefer and are more inspired by, but don’t pass the mic just because it isn’t your favourite track.
If you freestyle with a DJ, dare them to throw down beats you can’t freestyle over. Most DJs have lots of records they can never play out, so they are up to the challenge. Even better, invite or go and visit all your DJ friends and challenge them to give you their own unique instrumental set. After this, you’ll be ready for anything any DJ can throw at you, anywhere.