This video will tell you everything you need to know about QRP EFHW antennas, building the diy transformer for tuning with an internal tuner, and configuration.
https://www.*******.com/watch?v=s-_LyhdGapM
or google: Ultimate UL Portable Resonant Antenna Build - DIY Micro End-Fed Halfwave Matching Unit
During Max Gain, I always had luck with the 234' long wire, 3 degrees offset azimuth, sending traffic on the little black box. The key to the equation is where is your antenna in relation to the terrain around you.
If you're antenna is 50' off the ground, and the mountains that surround your town are 1000' elevation gain on every side, then it doesn't matter what you do, aside from a NVIS antenna setup, you're not gonna get DX.
KD2UUU