Memorize the table of colloid types. Key examples:
Sol (Solid in Liquid) - Paint, Cell fluids.
Gel (Liquid in Solid) - Cheese, Butter, Jellies.
Emulsion (Liquid in Liquid) - Milk, Hair cream.
Foam (Gas in Liquid) - Whipped cream, Froth.
Aerosol (Solid/Liquid in Gas) - Smoke (Solid in Gas), Fog/Cloud (Liquid in Gas).