The Aether Portal is formed exactly like a Nether Portal, but using glowstone and water.
Making a 2x2 pool of water, surrounding it with flowers, then throwing a diamond in lets you go to The Twilight Forest.
Nether Portals don't need corners.
Nether Portals have minimum sizes of 4x5. (length times height)
XP Obelisks are a good way to store your experience.
Grains of Infinity can be made using Fire Water, removing the requirement of flint and steel.
You can always suggest more Pro Tips for this pack at its project page on Twitch.
Use Eyes of Ender to hunt down the End Portal. They are made with Ender Pearls and Blaze Powder.
Gold is the best vanilla material when used as a tool, but cannot mine anything stronger than coal.
Just like in Borderlands, you can't swap out your tool's parts. 
Love tech? Can't find food? Eat the Battery Potato! If you've found a potato, that is.
Can't find coal? Find a nearby tree and smelt some logs. Then use that charcoal to smelt more logs!
Sleeping in the Nether or End will cause your bed to explode.
Never dig straight down.
The game is only as fun as you make it.
Easier rarely means funner.
If all you can hear is footsteps, it's a Creeper. I learned that the hard way...
Wood is the most versatile resource in the game.
You can reflect a Ghast's fireball by hitting it or even using your shield!
Placing a torch under gravity-affected blocks as they fall speeds up the process.
Ghasts have lower health than any other hostile mob.
Always bring tons of planks with you when exploring caves.
Catching on fire can easily drain an entire health bar.
Always keep a spare stack of blocks in your active inventory. Cobble usually works!
Raw meat is better than no meat.
Cliff overhangs and lighting glitches can spawn hostile mobs.
Check underneath a Diamond Ore block before mining it.
Parachutes auto-activate when falling off an island.
Cloud Parachutes can be crafted with four White Aercloud blocks. 
Golden Parachutes have twenty uses rather than one.
If you hear a lot of monsters, it's probably a dungeon.
If you hear a cave noise above ground, there's one nearby.
Don't take huge risks far from home....unless you have FTB Utilities.
Blocks can be mined faster if you time your clicks correctly.
Always check your surroundings before entering a fight.
If a drop looks too big, it probably is.
One plank is equivalent to 1.5 smelted items. Add it up!
Low on blocks? Houses don't need corners, nor do ceilings need perimeters.
Tools with stone mining levels can mine lapis, but not redstone.
Hitting F3 and H at the same time lets you see an item's durability, among other things.
You know, sometimes Pro Tips may extend off of the screen. Try upping your game resolution, or lowering your HUD scale. Maybe get a wider monitor. Can you still read this?
If you're brave, you can survive falling any height with water.
Add your own splash texts and pro-tips using the resources folder. Requires Resource Loader.
Do not taunt Saxton Hale.
A Techguns weapon's "dual-wieldability" can be determined by its hand-type.
Don't press W or S when bunnyhopping.
Press shift while bunnyhopping on the ground to trimp, which lets you jump really high at the cost of your momentum.
If you can't find a gun's recipe, it's probably made using some sort of crafting table from its mod.
MrCrayfish's Gun Mod's guns only require its crafting table and a lot of iron.
Never underestimate anything with a gun.
The One Probe can't probe anything.
Make more than what you need.
Twilight Forest has an Uncrafting Table, which requires a Maze Map Focus. Kill minotaurs or hunt one down in towers.
Use the Clipboard to list your ideas, projects, or store your thoughts. A Book & Quill is better at that, though.
The Upgrade Mining allows Item Transfer Nodes to become Cobblestone Generators. Be specific with your liquid placement.
The Upgrade Mining allows Liquid Transfer Nodes to pump water, but only from infinite water sources.
Blast jumping does not let you keep your momentum upon touching the ground. (In most cases)
Flan's Mods weapons are craftable via its various weapon boxes.
DungeonTactics lets you vault over fences by right-clicking them.
If you have a lot of wood and need storage, use a Small Storage Crate.
Get a storage system as soon as possible.
To save disk space, externally connect a drawer system (typically full of resources and common blocks) to your RS system.