First batch of salmon sashimi, tips for improving?

salmon sashimi is my favorite food and to save on money ive decided to dip my toes in making my own from the costco salmon. we got a big slab, my wife used half for a salmon bake for the family while i used the other half for experimentation.

after some research, i cut it into 3 batches to try 3 different methods:

first batch i thawed it, cured in salt, refrigerated it for 25 minutes, rinsed, and had to freeze again to have it for lunch the next day. this batch had good texture but came with a bit of a fishy taste. i got this method from this website:

https://vickypham.com/blog/costco-salmon-sashimi-sushi-poke/

second and third batches were made together but with different curing methods. thawed, salt cure and refrigerated for 1 hour, and marinated in rice vineger with ice and refrigerated again for 1 hour. second batch was just rice vineger, third batch was a mix of rice vinegar and mirin. drained, vacuum bagged, and frozen for 48 hours. these batches I didn't really taste a difference between the mirin and the non-mirin, but no fishy taste either. texture on the other hand was kinda rough, as you can see from the picture the outer layers of salmon were dryer. i got this method from this website:

https://mowisalmon.us/how-to-turn-raw-salmon-into-sushi/

it was my first attempt so i wasn't expecting perfection, overall it was a good experience and im glad i tried. but for my next attempt i would like feedback on how to improve, where did i go wrong? which method is better to improve on?

i would like to add that this excursion and photo were a few months ago, so I don't have the best memory of the results other than what i wrote down in my notes. anyway, any advice would be greatly appreciated