There are lots of training drills you could do that will help to improve your technique in this area, but you have to adapt to your situation in the actual match.
Well basically, the main reason for a run is creating space thus giving you a chance to run and attack the opponents goal.
In this diagram, the defenders do not see the attackers run as dangerous because he can be closed down very easily if the ball was passed to him as there is little space between himself and the defender.
In this diagram both defenders have been decoyed into poor positions by the blue player with the ball, and the other blue player has made space for himself by standing still
, then he could make a run on the path of the dotted line providing an easy, but very effective attack.
This was a dual effort by both blue players to make space for the attacking player.
This diagram shows a decoy run where the attacker with the ball is facing 2 defenders in good positions.
The attacker with the ball pretends he is going to run at the two defenders on the yellow line. The 2nd attacker runs on the blue dotted line and the attacker with the ball makes a pass to the right hand side of the orange no.9
(Orange team attacking)
This is basically a check-back situation.
In diagram 1 the orange number 8 simply moves towards his teammate for a pass and brings the defender with him. This situation robs the orange team of the space they want to use, players can end up on top of each other, and makes it harder for the number 8 to control the ball.
In diagram 2 the number 8 first moves away from the space that he wants to use and the defender follows him and tries to stay goal side. The number 8 then cuts back quickly towards the pass. This helps to keep the space open between the attackers and helps to back the defender off of the number 8 as he will have a hard time making up the lost first step. Checking back can also be used with the deep pass. If there is enough space between the two attackers the player who will receive the pass first moves towards his teammate. Then, when he has drawn the defender in, he can turn quickly and move back into the deep space.
Diagrams from http://www.bettersoccermorefun.com