Perform for a recording. Use your phone, tablet, computer or whatever you have available.
Listen critically to the recording afterwards. Make notes on things you can improve. Then practice recording again, listen again, record again, listen again, and so on.
When performing do not aim for perfection, aim for an engaging and communicative musical performance. You are presenting art, not a score with a bunch of notes.
Practice intentionally messing up and recovering in various parts of the music. Don't forget to practice the obviously easier parts of the music too, it is far too easy to neglect these parts and only practice the difficult sections.
Practice music starting at random points in the piece. Avoid always starting practice at the beginning. As much as possible, avoid developing a dependency to start at a a specific part of the music in order to get the fingers moving. Develop the ability to start playing the piece from any point, that includes uncomfortable start points.
If you mess up at some part of the piece, be musical and creative about it. Keep going, or if needed cadence gracefully and resume at the next phrase. Look forward to the next part of the music, do not dwell on a mistake you just made.