This not a fullproof but still a tryable list of things to do to to lower your risk of detection by your ISP if you are using BitTorrent.
1. Enable encrypted stream for downloads in your BitTorrent client so that your ISP doesn't know what you are upto.
2. Try not to download contnet from users wh have older versions of BitTorrent. You can do this by enabling "Disable legacy client" setting in the BitTorrent client.
3. Use Peer Guardian and P2P block to control and block incoming and outgoing connections from your computer.
This simple guide is not complete without your sugegstions.