Don't make this mistake!
"The single biggest mistake that most beginners make is putting 100% of their effort into the positive (concentric) part of the rep, while paying no attention to the negative (eccentric) segment." - Dorian Yates (6 Time Mr Olympia)
TIP OF THE DAY: Don't neglect the eccentric portion of the exercise!
Example: While doing a flat bench press or squat, don't just focus on the way up. Pay attention to the way down! Control the weight and focus on that mind-muscle connection, not just on moving the weight up or down.