Minecraft wiki entry for Tutorials, associated text: Custom texture packs — texture packs are no longer used, resource packs use new file structure
How to get a crash report (Outdated) — no longer works with the current launcher
Water tram - Boat mechanics have been overhauled
Managing slimes in superflat mode — slimes are no longer a plague
Repeater reboot system — a glitch that existed in Beta only
Update LWJGL (Legacy) — current launcher automatically updates libraries
Custom lake — these methods are no longer needed since water is more obliging
Water ladder — no longer works as given, water behavior has changed a lot since Beta
Installing mods - Modloader — ModLoader is no longer supported by its creator
Far Lands — they were removed in Beta 1.8
Instant wire — a glitch that existed in Beta
Update Minecraft — updating and downgrading Minecraft is automatic in the new launcher
Minecart booster — Minecart boosters were fixed shortly after the introduction of powered rails.
Survival with no enabled data packs - Blocks no longer drop items when data packs are disabled with the Village & Pillage update.
Door-based iron golem farming - Villages are no longer based around doors with the Village & Pillage update.
Village chaining - Villages are no longer based around doors with the Village & Pillage update.
Potion farming - Potion farming was patched in version 1.17.3 as a result of being too overpowered.