Just some things I do that may or may not be useful to you.
I register for as many of the games I want to play off-merchant hall hours as I can. While I do still attend plenty of games during merchant hall hours this allows me to wander the merchant hall more. I'm usually gaming as early as 8am or 10am until midnight with a short lunch break at the food trucks and around a two hour break for a sit-down dinner, but I usually make sure I leave at least a couple hours to wander the merchant hall.
There's usually a group of us that go together and we try to have a sit down meal together with as many of us as possible for dinner. It's a good way to just relax for a bit, talk, and still feel like we're a 'group' even though we might have been off doing our own thing most the day.
I carry a well insulated water bottle full of ice (usually filled with lemonade), maybe a single can refill, top it off with water once in a while and some small snacks (candybar, nuts, whatever).
I have a tablet I carry with me that has all the info I need for everything I want to do, but I typically have a physical print out of the convention maps and my schedule, with my even locations marked.
Typically I'll avoid the opening of the merchant hall doors and just play a game in the mornings instead. Unless you're trying to get your hands on something that's going to disappear fast and can't be bought later (after the Con). The crush of that initial rush each morning just isn't worth it to me.
I don't actually formally register for all the games I want to see in action or learn (in order to decide if I want to buy them). Sometimes I just make a note of the time slots and only show up to watch. This way, once I get a feel for the game, I can stay or walk away without creating a negative situation (walking out on a game or just vanishing). I do this more often with RPG's than Boardgames.simply because I find that once I get a feel for how characters are built and the basic rules work in an RPG I have a decent idea of if I"m going to like it. With Boardgames I find I want to a more direct experience with the game. Also, I find getting stuck with people you're not a fan of tends to be worse with Roleplaying than just playing a Boardgame.
If something is easily bought after the convention, rather than during it, and is going to pretty much cost me the same later, I'll grab a business card, or catalog, or whatever and wait. This way I'm not packing a bunch of stuff home with me.