The fundamentals of any game are important if players are going to succeed at higher levels. Look at the best players in the world, they all have a solid fundamental base that makes the simple parts of the game seem effortless.
Passing, trapping and dribbling are essential parts of the game of soccer. Repetition is important and getting as many touches on the ball as possible in any given session will help develop these skills as well as confidence if performed in the proper environment.
Technical training needs to be success oriented and goal oriented with proper technique emphasized in every exercise. It also helps if the drills are varied to alleviate boredom, loss of focus and also because situations vary in the game of soccer. Creating a competitive environment can go a long way towards creating enthusiasm while mastering the fundamentals.

Start with the basics; good passing, accurate with the right pace so the player receiving the ball can receive it and be able to look for the next pass, shot or play;  good trapping, soft touch with the body positioned behind the ball, keeping the ball close so the next pass is easily made and defenders can’t step in and steal it.

It is important to instill discipline and have expectations of completing the given task to a high level of competency level when teaching fundamentals. Do not let your players advance to B until A is complete, meaning done correctly and with confidence.

Once they are completing A, B and C competently then make sure drills are moving quickly and everybody is involved. Make drills success oriented with several tasks involved, including running/fitness.

The Ajax system of training has some great drills that cover fundamentals.