Foxes are often creatures of habit and tend to have runs that they follow on a regular basis. At least that has been my experience of them in Kent, Leicestershire, and Somerset. Finding the regular path might be a little harder. They tend to follow edges and natural lines, wood edges, fence lines, hedges, ditch edges.
The cubs, if you have any, are noisy when they come out to play and will be found in the general area of the den through till early/mid summer, the young stay pretty dumb right out till autumn. I have stood on the lower rail of a 3 rail fence and had a youngster trot along and smell my boots
Have you tried calling? Mouse squeals can bring foxes in from 50+ yards if the wind is right.
From my limited experience of plantations, they seem pretty lifeless places and while a fox might make a den in there, they will be doing thier hunting outside. Chances are they will have definite places that they leave the cover to start hunting.
Best of luck