It's been, said but truly the best thing you can do is just do sooooo many games untimed (this is crucial), all the time. I started at the same diagnostic as you and had a lot of trouble with the games. Within two months I got my self to consistently -0/-1 by doing multiple games a day in a really casual way until it felt natural. I would do them while eating lunch, while waiting for the bus, between tasks at work etc. I always did them untimed and gave myself as much time and grace as I needed to get them right. Eventually, it turned into a fun thing (gag! I know) that was more like taking a break to do the crossword than doing a test. This helped me really reduce the panic that I initially felt with LG which I think is how improved my score so much. Once I was consistently getting -0 individual games I would start doing multiple back to back and soon it became natural. I am very wary of giving specific advice on LG (i.e. order of operations, how to draw the board, etc), because I really believe that different things work for different people and forcing your brain into a formulaic method that doesn't work for you is going to do more harm than good. You will figure out the technique that works for you by doing a lot of practice and trial and error.

TLDR is that in my opinion, approach these as a fun, relaxed thing that you practice casually everyday and it will take away a lot of stress and angst. Good luck!