I have tried every imaginable workout method for abs and legs, from lifting heavy to doing some kind of leg workout everyday as is promoted by Lower Body Solutions.
I have found, and this was suggested to me by a trainer last winter, that working legs only 2 times a week with low weights and high reps works the best. I've kept track of my workouts and this is what I've done since last December. I only work abs 2 times a week. I also do step aerobics at least 2 times a week which some thing "bulks" your legs. I have not found this to be the case.
I do not floor work, only one inner thigh exercise, and no outer thigh exercises except for kickboxing, which works your outer thighs.
That being said, everyone is different, so you have to try and tweak as needed.