I used iron knives, but you can also go cannon route.
If you're going cannon though I'd suggest doing slayer at the same time to recover a little cost.
As someone else said higher metal knives would also work.
At 55 slayer you can use Broad Bolts, same price as mith but do the damage of adamant.
Chinning is also good, but not worth it at lower levels. Plus you can't equip the chins if your low anyway.