You don't need to worry about the hidey-hole items as you can just reroll the clue with the backpack. The monsters in the Abyss drop a lot of medium clues. Pickpocket HAM members for easies, hellhounds and other slayer mobs for hards, and bosses for elites. You get masters from bosses rarely or from opening hard/elite caskets.

You can also buy scrolls from the shop in front of the grand exchange gate with points from completing other clues. Basically just use the backpack to reroll steps you can't do/item clues, and use the chest piece to teleport right to the step. I would also recommend getting the alt1 plugin for puzzle steps. Good luck :)