During the Malayan Emergency (1948-1960) 22nd SAS developed a method of inserting patrols by parachute into dense jungle.  Instead of an approach march of several days, a patrol could be parachuted into an area in a matter of hours.

The technique as instigated in 1953 was simple; the parachutists jumped into the jungle canopy carrying 100 feet of rope. 

Once the parachute canopy had snagged in the upper branches of a tree the man would tie the rope to the tree and lower himself to the ground.  However, it was soon discovered that many trees grew to a much greater height, so the amount of rope carried was increased to 200 feet.

After a while, the technique was further refined using parachute webbing instead of rope and the development of a “bikini” type harness to support the parachutist as he abseiled to the ground.

There is some interesting newsreel footage on YouTube:

British Pathé: Special Air Services Regiment, Tree Top Drop (1954)