I'm hesitant to train Dungeoneering, as it seems to be team based and... I prefer solo training.
However, looking over the dungeoneering rewards, there are some items I really want. I'm going to briefly run through the items I want.
Gem Bag (2000). This item stores 100 mixed gems, so would be perfect to take on slayer tasks, as I usually leave gems. When it finally got full, I could empty it and it would be worth around 300-500k.
Bonecrusher (34000). This sounds amazing, even though I'll need to get about 70 dungeoneering for it, so it's more of a long term goal. What it does is if a monster normally drops bones, the bonecrusher converts them into prayer xp without any clicks! This means all the big bones, normal bones etc will be buried without any effort from me, leading to easy prayer xp.
So, after 90 slayer I will try and obtain these 2 items, to help me slay better.