Block Tackle
As well as the sliding tackle there is the block tackle. For both you need expert timing, to reduce the risk of making a foul and also sustaining/causing injury.
The correct time to make the tackle is when your opponent shows you the ball. This means that they are not protecting the ball from you, allowing you to get your legs in and win the ball.
The simplest technique is to move one foot forward, bending it at the knee, then with your second foot, move in and take the ball. To improve your chances of winning the ball put your full weight into the move and reduce injury risks by only using the inside of the foot.
When making the tackle it is important to go into it fully committed. As if you are not then you may come off weaker and possibly sustain injury.
Sliding Tackle
The slide tackle is an aggressive tackle used to capture the ball at ground level. Because it takes place at ground level it is dangerous, and if done incorrectly or hesitantly can result in an injury to yourself and/or the opposing player.
The tackle is made by sliding your body and feet forward simultaneously, timing things perfectly to connect with the ball first hence dispossessing the player. You must keep your feet low or risk a foul/injury and ensure that you approach from an angle.
One drawback with the tackle is that it leaves you on the ground, so if mistimed it can result in the opposing player being able to run onwards unhindered.