yeah, tension is such a fickle creature. I used to be an extremely tight knitter, but I’ve loosened up over the years. But there are definitely influences out there - how tired you are, how stressed out you are, how warm or cold you are, how much you’ve been drinking (maybe this is only me? :shifty: ), etc.
Practice will help to even it out, and you can also look at how you hold your yarn. Sometimes the way you hold your yarn can contribute to your tension. I don’t know if I can explain, b/c it’s just something I’ve noticed. When I first started knitting I was doing my version of continental - holding the yarn in my left hand but wrapping like english style. I noticed that the way I was holding the yarn to do this style resulted in my tight work. I made myself learn the “proper” way to do continental, and I started holding the yarn like Amy does in her video, and my gauge started loosening up. Not too loose, still a little on the tight side, but good enough for me. I generally only have to go up one needle size now, as opposed to 3 previously.