I had good luck recently tweaking a Fontana Cab kit for maximum flavor. Fontana is not an expensive kit so I wanted to tweak it up a bit. I under-diluted it so I was making only 5 gallons instead of 6. I added 2 lbs of Star Sapphire grapes (crushed) and 2 lbs of blackberries (crushed) to a polypropylene bag. I made this in the spring so the grapes and blackberries were from S. America. I used whatever yeast was in the kit. I let the wine ferment on the grapeskins/berries (tried to keep it on the cool side, in the mid to upper 60's F) for about a week and then removed and squeezed out the bag. Drank it recently after 5 months and it was surprisingly good. We had some friends and family over for a gathering and they could not believe it was homemade wine. Also, it was better than a more expensive Cab kit I bought a year earlier that did not have any grape skins. The grape skins really make a lot of difference, and the wine has a subtle blackberry taste.