Although Minecraft doesn't have to be played in a certain way, there are benefits to play Minecraft in this way, often getting you killed less.

Things not to do

It's very helpful to have some tips on things to not do in Minecraft. These can save your life. Hopefully, you know most of them, but you can only be too careful.

Don't dig straight down

This is a bit of a no-brainer. If you dig down, you could land, unprepared, in a mob-infested cavern, an abandoned mineshaft, a stronghold, a dungeon, lava, or even a deep ravine. Those are generally not approved for health benefits. It's better to dig in a staircase pattern. This goes double for the Nether and especially the End, where overhangs and drops (into lava or even the Void) are all to common. The only safe way to mine straight down is to have a water bucket in the hotbar slot next to your pickaxe/shovel and MLG water, which is smash your right-click while holding water to prevent fall damage, or look up and right-click the nearest overhang if you end up in lava, but it is still not recommended at all.

Don't dig straight up

This one isn't quite as obvious as the previous one. However, if you dig straight up, you could end up in the middle of an ocean, for one. Another hazard is lava pouring down on you, not to mention a nasty mob or sand/gravel falling on you. Again, it's always best to dig in a staircase pattern. Also, if there are particles falling from the ceiling, don't dig; blue is water, red-orange is lava, and green is a Slime. 

Don't always wear diamond armor and use diamond tools

Iron is pretty sufficient. Also, not all dangers are in fights; unless it has Fire Protection or Feather Falling. Your diamond armor, should you fall into lava or a deep chasm while mining, will be pretty much useless and be lost unless you're quick. Also, it's best to save your diamond pickaxe for obsidian; iron mines everything else just fine.

Don't melee attack Skeletons

Skeletons, as of 1.5, became much tougher in melee combat. If you get close, they will start shooting faster and harder. A Bow is the best weapon for defeating them.

Don't neglect food

Food = life. Life = good. You need food. Make sure to set up a consistent source of food. This means a farm. Animal spawns are not consistent. Would you like to live your life on Rotten Flesh and Spider Eyes?

Note- if you are laying on Peaceful mode your food will not deplete itself

Don't try to mine most ores with a golden pickaxe (including gold ore)

Golden pickaxes can only mine the blocks that wooden pickaxes can mine, also gold is the only pickaxe material that cannot mine the block it is made out of, however golden pickaxes are useful for mining stone and coal ore in a very short amount of time.(Even though gold pickaxes are the most fastest pickaxes.)

Don't go afk without pausing

A lot can happen in a few minutes. A creeper could spawn in a neglected corner and come wandering towards you. A skeleton could find a vantage point that allows it to shoot you. And of course, if you are gone for over 5 minutes, you could come back to find yourself dead, and your items despawned. Even on peaceful, you could get pushed into a ravine by a passive mob. You could get hit by lightning (but it is unlikely). Just take sensible precautions before pausing your game.

Good things to do

These will help you survive longer

Spawn base

Unless your base is right next to your spawn point, you have made a bed and slept in it, or you are playing on hardcore, then build a small hut next to the place where you spawned. This way, if you die at night, you don't have to trek back to your base completely unequipped.

Know your hot bar

It is so useful in a fight to be able to know where all your weapons are. Picture this. You are mining in a deep cavern, when you break open a wall and multiple mobs are washed towards you. If you know your sword will be in Slot 1, you don't have to waste valuable time cycling through your inventory looking for something to fight with.

Always have a backup

When you are mining, don't use up every single pick. What if you get lost, and need to dig your way to the surface? Likewise, always have a spare sword, so if your first one breaks, you don't have to flee in panic.When mining,it is recommended to bring more than a stack of blocks.