For kosher salt, you pretty much want Diamond Crystal (Keller calls for it by name, and AB apparently does ad work for them now). It is more pure than the best competing brands, and has less weight per volume (and maybe only half the weight of table salt; yes you're eating less salt for how much appears to be in your hand), making it easier to be precise with. Kosher salt has a particular structure and size, and that's why you'll always seeing it called for all the time. Don't get me wrong, I use fine sea salt, coarse sea salt, pink Himalayan salt (very salty, but very good), etc, but am still using kosher more and more exclusively for the cooking part. One of the main reasons why salt helps to increase flavor is because it is an electrolyte, and essentially excites the sensors on the tongue.
Salting your meat in advance, say on your steak while it sits on the counter to come to room temp, also has a particular function, it's denaturing the proteins, and trust me, it tastes so completely different between salting an hour before cooking, or immediately before cooking. I ran into the below entertaining pic a while ago.
Oh, on my hunt for the best salt and pepper mills (after getting fed up with my cheapies from a local grocery store), I went with Peugot, quite expensive, but totally worth it, not only because I don't have to go through the PITA of taking it apart from the bottom, with a tiny screwdriver, trying to smush the rectangular arm back in through all the packed coarse grains, etc, to refill it (Peugot has a magnetic top which simply comes right off, pour stuff right in), it also is adjustable for the size of grind, particularly useful for pepper, for me.
