A weak grip is a common cause of a slice. The good news is that it is easy to check and correct. Looking down on your grip you should see two knuckles on the left hand and the 'V' shape between the thumb and forefinger on your right hand should point to your right shoulder. If you have a weak grip, you will see fewer than two knuckles on the left hand, while the 'V' on your right hand will aim at your chin.
Golfers who struggle with accuracy on tight courses often get distracted by thoughts of the trees rather than concentrating on where they want to hit the ball. Invariably, wherever your thoughts go, your golf ball follows.