How do I survive EASILY on the non-peaceful difficulties?

Make a sturdy house of Brick/Stone/Cobblestone. Obsidian makes the best building material (completely blast proof). Most anything else takes too much damage from Creepers. Make sure there are no holes, multiple doors and some windows (to see if there are mobs nearby).

Light up the area near your home with generous amounts of torches/glowstones/jack-o'-lanterns. Also light up mines and paths. The more light, the fewer hostile mobs.

Use a bed at dusk to prevent new hostile mobs from spawning.

Carry food with you (cooked porkchops are one of the best) so you can heal yourself.

Armor is always a good idea (do NOT use gold), and weapons are a must. Swords (minimum stone, iron is better and diamond is the best) do a good amount of damage, but bow and arrows keep you at a safe distance (and are the best way to slay ghasts).

Build moats/traps near your home to kill/incapacitate hostile mobs. Cacti fences (stagger them like a checker board) work wonders. Fire does steady, passive damage. Lava kills quickly. Beware-all mobs (except Slimes) can swim, but only on the surface. Neither fire nor lava can damage zombie pigmen or ghasts.

Do not venture out at night. Having a clock can help you out if you cannot see the sky.

Zombies, Creepers, and Spiders can easily be beaten by jumping into deep enough water (3 blocks deep minimum) and attacking from below. Beware, Skeletons and Spider Jockeys can still get you. Slimes sink and become immobile in deep enough water (1 block for small, two for medum and three for large).

Don't attack wolves and don't attack zombie pigmen unless you are prepared for a massive fight.

Even the most seasoned players die easily. Should you suddenly be mobbed by mobs, you can always save, quit, and reload in peaceful to force all hostile mobs (except Slimes) to despawn.

If you don't want a clock then go under water and you can see the sun through the clouds,you can't see through bricks though.build your house near water so the monsters can't interupt your sleep.I would also tame dogs if you keep getting killed by skeletons.good luck

Tame dogs. Build a sturdy and dependable house (obsidian works best) and immediately mine to get cobblestone diamonds and iron to make swords.