I wish to see more skills follow the version of my favorite skill, Slayer, that will be about killing monsters assigned by Slayer masters. Slayer makes training your combat skills more enjoyable by taking you around Runescape, also because it enables you to fight so many distinct creatures, you get item drops which fuel a variety of non-combat abilities --gems for OSRS buy gold, seeds such as Farming, metal bars for Smithing.
I'd love to see that kind of diversity come into skills like Herblore and Agility, and I'd like to see more skills interact with different abilities, like how I coached Woodcutting when leveling Hunter. Efficiency is enjoyable, and Runescape is at its finest when you're not stuck doing something.
Happily, a few of Old School Runescape's more recent updates introduced minigames that assist liven up otherwise boring skills like drinking and Firemaking. And while some skills are still dull to train, they are at least more rewarding as a result of the addition of skill-gated regional diaries which give you a globetrotting to-do list--kill this creature, speak to this NPC, complete this exploration, craft this product and so forth.
Completing diaries unlocks exceptionally buy Runescape gold useful utilities and shortcuts, so they inspire you to train skills and complete quests. They also offer a small but precious dose of direction: if you want a new target, you could always work on your own diaries.