Hey, Jack here giving you a 1-99 Firemaking. This is the way I did and I'm sorry for not knowing the right amount, best way to get xp is bonfires. World 100 at the shanty Pass is the best place for bonfires because if there is more than 10 on a bonfire there is a small bonus.

1-15 Normal logs, either cut them or buy them cheaply of the Grand Exchange
15-30 Oak logs, again cut them or buy them off the Grand Exchange, they are fairly cheap
30-45 maple logs, These are extremely cheap so I advise buying them
45-60/83, now there are two ways, you can either do them to 60 and do yews to 83, which are fast but can be costly or continue with maples which are still fast and cheap but not as fast as yews.
83-99 Now this is what I did and is the best and fastest firemaking xp on the game, Jadinko Lair. This is completely free and it's only requirements are 83 firemaking and 83 woodcutting. Its the best because its free and its 320k/hour and 60-80k woodcutting xp too.
if you cannot do Jadinko lair because you don't want meet the requirements or don't want to you can simply do maples to 99 which are cheap or you can do yews to 99 which are alot faster but more expensive.

Bonus:
Ring of fire
flame gloves
inferno adze
They will all help with the xp per hour alot and you obtain these you do the Beacon minigame in the wilderness(advised to watch a full guide on youtube).

Thank you hope this helped and enjoy getting 99 firemaking

Thanks for posting this Jack, as a suggestion why not try including the quantity of logs needed and how much it would be (at this time) to buy them? Also try adding a few pictures in to

It's so nice to see guides coming back, if you need any help with this please PM me, I'll gladly give you a hand.

I know, but I din't know the correct logs and how to work it out and stuff I just saw a guides section and thought why not make a firemaking one, it was just quick thinking but it's how I got it