There is an awful lot of quality information available for free. Here are a few links I have posted in the past. YouTube channels for Raceboy77, Skip Barber Racing School and The Racing Line are just a few of the good ones. I suggest searching for what you are looking for, then applying it in your practice, in rivals mode.
http://forums.forza.net/turn10_postst61673_Interesting-Article-on-Passing-Etiquette.aspx
http://forums.forza.net/turn10_postst61719_The-Racing-Line.aspx
http://forums.forza.net/turn10_postst61726_Brake-Like-a-Pro.aspx
http://forums.forza.net/turn10_postst61724_Cornering-like-a-Pro.aspx
Exit: here are some from Raceboy 77
Racing In Traffic Traffic Racing and Starts (Forza Tips) - YouTube
Cornering Tips. Cornering Tips (Forza Tips) - YouTube
Clean Racing Tips. Clean Racing (Forza Tips) - YouTube
Braking Tips. Braking Tips (Forza Tips) - YouTube
Assists, and The Racing Line Is A Lie. Assists and Braking Line is a Lie (Forza Tips) - YouTube
Shifting Tips. Shifting (Forza Tips) - YouTube
Here are some more. I hope I didn’t repeat any. I will check for redundancy once I get them all here.
Advanced Driving Techniques - Setting Up The Pass - Tips from Pro Drivers
Advanced Driving Techniques - Defending vs Blocking - Tips from Pro Drivers
Advanced Driving Techniques - Late Braking - Tips from Pro Drivers
Advanced Driving Techniques - Is Smooth Really Faster? - Tips from Pro Drivers
Advanced Driving Techniques - The Perfect Lap - Finding Those Final Tenths
Advanced Driving Techniques - Hitting The Apex
Advanced Driving Techniques - The Fast Line - Tips from Pro Drivers
Skip Barber - Going Faster
Racing in Traffic - Part 1 - Situational Awareness
Racing In Traffic - Part 2 - Making the right moves
Passing - Know How To Dominate
Oversteer - The Party Drug of Driving
Braking - Brake Yourself Fool
The Racing Line - The Only Line You Need
Shifting - Don’t Be A Shift Knob
Tuning
Worms Forza 6 Tuning Guide
http://forums.forza.net/turn10_postst48522_Tuning-Guide-for-FM6.aspx
The only thing I can’t seem to find is How To Avoid or Overcome the Over Aggressive Drivers. No matter how much you practice, there will always be those drivers who can’t seem to be competitive without bumping, pushing, punting and side swiping to gain and maintain the lead.
If you run across anything to help with THAT, I would be very interested in the link.
Enjoy good clean racing!
Clean Laps Matter
Peace