looking for things similar to:
- Tears of Guthix minigame
- Bird house trapping

if anything similair comes to mind, please let me know. Thank you

Tree farming!

organized crime is on a timer - if you try hard && it's not crowded then it's great xp for niche accounts (accts trying to keep hp low while raising combat stats, or trying to get hp xp, or training range/mage for poor accounts maybe iron men). it's not really worth the effort if you're a normal account

Passive income can be considered too, as it will give money for faster xp rates.
Kingdom + Battlestaves are two that come to mind
Farming
Maybe can consider doing agility well you think of what to do.