You can check this book for your improvisations "Jamey Aebersold - ii v i progression" and there is play alongs with it (:
For your fills, my comment is listen a lot and play what you like (:
Hi guys it's GhettoShred.. m playing bass since 2011 and my fav styles are Fusion, jazz and Latin popsih (:
well, m playin an mtd 635-24
if you want to know more, feel free to ask
Love
From Turkey, greatings
-GhettoShred