Below is a version of the end fed zeppelin antenna for six meter and 2 meter operation. The dimensions are a little on the long side but not by much so don't get carried away pruning, it is much easier to trim than to add to the length.

This antenna is 3.5 wave lengths on six and 10.5 wave lengths on 2 meters.

Put antenna at least head high off the ground and away from metal buildings, houses and cars etc. these will mess up your day when tuning antennas. If you must prop the antenna up in the center to maintain at least 4 feet above ground.
Tuning is only a three step process. First trim wire number 1 ( the long one ) for the lowest vswr ( not necessarily 1:1) you can get at the desired six meter frequency.
Second trim wire number 2  for the lowest vswr, should be less than 1.5:1 if not you goofed some where.
Third trim wire number 3  for the lowest vswr at the desired two meter frequency, again should be 1.5:1 or less.
Take your time here, as they say a little dab will do ya. Trim in 1/8 inch increments.
 

Below are plots for the antenna, the red pattern is the vertical component of the RF field.