improvise
– create and perform (music, drama, or verse) spontaneously or without preparation; speak impromptu

• A good actor should be able to improvise in case he forgets his dialogue.
• The pianist improvised an accompaniment to the song.
• Carnatic musician Dr. V.R. Dilipkumar is an expert in raga improvisation.

– produce or make something from what is available

• An improvised meal for unexpected guests
• We improvised a mattress from a pile of blankets.

improve = become or make better

• Her health is improving
• The government should take measures to improve the living conditions of the poor.