I just started weightlifting about a month ago (with practically no base), and right now I do on average 3x10 for all exercises. If I'm not tired after the 4th, I'll keep doing sets of 10 until I get to a set where I can't finish 10. My friend told me that'll tone more than it'll build muscle mass. He said I should try higher weight and go for 3x6 for a lot of the bigger muscle groups. What do you guys think?