🚀 - there's a decent cannon spot to increase the kill rate. Note that cannons cannot be used in Kourend Dungeon at all.
💦 - using Ancient Spells from Desert Treasure, typically Ice Burst (level 70 Magic) in a multi-combat zone for fast Slayer/Magic xp.
💀 - there's a Boss alternative (Zombie = Vorkath, Abyssal Demon = Sire, etc). Not to be confused with the "Like a Boss" unlock task row.
💎 - the monster resides in Kourend Slayer Dungeon. Doing tasks there gains Ancient Totem pieces to do Skotizo, Ancient Shards to recharge Arclight, and bonus Prayer points for burying bones (works with normal Bonecrusher).
💪 - there's a Superior monster on this task, giving you a chance at Eternal Gems and Imbued Heart.
🐉 - weak to dragonbane weapons (Dragon Hunger Crossbow/Dragon Hunter Lance)
👹 - weak to demonbane weapons and spells (mostly Arclight)
Monkeys - Demonic Gorillas requires paying attention, therefore it's a Boss. It even has it's own killcount.
General note: Slayer Helmet DOES NOT STACK with Salve Amulet. If you are doing Vorkath with ranged, use Elite Void and Salve amulet. If with melee, it is better to use full strength + Salve + Fremmy full helm. For Vampyres use Slayer Helm + Flail + Fury/Torture.