MNEMONICS

For Halogens:

Fluffy Clouds' British Invasion

Flan, Claret, Broken Ice

Flowers, Claret, Brilliant István

Flowers, Claret, Brooding István

For more elements:

Harry He Likes Betty But Can Not Offer Flowers. NeNa Mcgee Always Sips Pure Sweet Claret/Chlorine.

For the Great Lakes:

• HOMES
• SuperMan Helps EveryOne
• Sam's Horses Must Eat Oats / SuperHeroes Must Eat Oats.

Cranial Nerves:
On Old Olympus's Towering Top, A Finn And German Viewed Some (Actual) Hawks.

Luminous spectrum/rainbow:
Roy G. Biv.

Continents (has all the As served up by two initials, the Americas separated):
Eat An Aspirin After Augmenting Noah's Common Ship (Ark)

Colour code in transistors:
Blake Boys Rape Our Young "Grrls", Blue Violet Goes Willingly (for Gold or Silver).