Many coaches wonder how much time they should devote to skills related drills vs. time scrimmaging or spend doing other practice game elements. My answer is always the same: Spend as much time as it takes for your players to properly grasp the essential soccer skills and demonstrate the fact.
Learning to trap, dribble, and pass are the basis for all play. You make your players skillful doing all three by giving them lots of touches on the ball at practice. Be it skills drills or game drills, the more chances to control and carry the ball your players get, the more comfortable they will become in the long run and the better soccer players they will become.
With that said, players become bored if you spend too much practice time doing less less active and eventful skills drills. In my opinion, one or two skills drill practice is plenty, and I would prefer to spend 65-75% of my practice time in small-sided games, and other scrimmage-like elements.
The idea is to make sure your players show during the scrimmage games what you have taught them in the skill drills. For example, dribbling the ball properly means keeping the ball within a touch or two, and keeping your head up, scanning the field. If your players are not demonstrating proper technique when they dribble, you obviously need to spend more time doing soccer skill building drills in this area.
Do not spend too much time covering the basic skills if your players demonstrate that they know what they are doing when real games come around. If not, spend as much time doing skills drills as you need in order to make your players comfortable with the ball.