In order to lower your entry fee I would suggest acquiring access to the Ring of Charos (a). But, do not use the 'pay' option with your Blast Furnace foreman as OSRS Gold it can void the benefits of the ring. This ring is available during The Creature of Fenkenstrain questline.

The addition of Ice Gloves in the Blast Furnace will be beneficial when you're making use of the bar dispenser since they'll cool your bars in a short time for you to use. This will help you save time, instead of having buckets of water to cool your bars (and it'll help you save space in your inventory as well).

Before you embark on getting to the Blast Furnace itself it's important to know that it's only accessible to those who live in these worlds 352, 355, 358, 386, and 387. Once you've sat down with the Giant Dwarf, and then entered Keldagrim, you need to: Head north and make your way across the bridge. After you've crossed the bridge, continue heading south until notice the Blast Furnace icon on the map. Enter the building marked go downstairs, and you'll be able to see the furnace.

After this is done you'll have a much easier time to go there in the future. You can use the Grand Exchange shortcut on the northwest wall, or take to the minecart to explore Ice Mountain mines for dwarves or make use of the minigame group locater that will let you enter the building.

It may take some time to get familiar with at first but the minigame with the Blast furnace is very easy. For the furnace to be used to operate, follow these steps. Then, deposit your ore on OSRS Gold For Sale the conveyor belt. Go down the ramp with a bucket full of water or ice gloves. Then cool down your bars and deposit them.