Bounds - Explosions
Some people make these triggers, which arn't very good:

CONDITION:"Force 1" brings at least 1 Zerg Zergling to location "Level 1"
ACTION 1: Create 1 Protoss Reaver at location "1A"
ACTION 2: Kill all men for "All Players" and location "1A"
ACTION 3: Preserve trigger.
This trigger doesn't use Switches and the level won't stop when you past it. It starts all again if you touch the location "Level 1".

This is how I make my bounds:

CONDITION: "Force 1" brings at least 1 Zerg Zergling to location "Start Level 1"
ACTION: Set "Switch 1"
The trigger above just starts the level.
Then I make a new trigger for the explosion.

CONDITION: "Switch 1" is set. ACTION 1: Create 1 Protoss Reaver at location "1A"
ACTION 2: Kill all men for "All Players" and location "1A"
ACTION 3: Wait for "100" miliseconds.
ACTION 4: Create 1 Protoss Reaver at location "1B"
ACTION 5: Kill all men for "All Players" and location "1B"
Keep repeating the actions above until your level has ended.
ACTION 6: Preserve trigger.
When you preserve the trigger, it means it repeats itself. Then to stop the level, make this trigger:

CONDITION: "Force 1" brings at least 1 Zerg Zergling to location "Start Level 2"
ACTION 1: Clear "Switch 1"
ACTION 2: Set "Switch 2"
This triggers ends the level and starts the second level. Repeat this over and over until your bound is finished.

Bounds - Fire
Most bounds have fire to dodge. They are mostly Dark Archons. Sometimes units patrol and you have to pass them. This is how I make my fire triggers.

CONDITION: Always
ACTION 1: Center location labeled "P1" on "Zerg Zergling" at location "Anywhere"
ACTION 2: Preserve Trigger.
This triggers makes a location that moves on the Zergling where ever it goes. The next trigger is how the Zergling dies.

CONDITION: "Player 8" (the player that is the fire) brings at least 1 Dark Archon to location "P1"
ACTION 1: Kill all Zerg Zergling at location "Anywhere"
This means, if the fire touches the location "P1", which is on the Zergling, it kills it.

Cloaked Units
Disabling Doodads- (You need a special editor for this, I use X-tra editor.)

This can do many things, such as cloak beacons so they look embedded into the ground. Or cloak certain buildings/units.

ACTION: (SET DOODAD STATE) Disable doodad state for Terran Beacon for "Player 1"