As the title states what's the quickest way to get to 100 smithing from 70 did a bit of research and it turns out the dagger method has been nerfed I also choose the light armour path so making heavy stuff is out the question

Build a Hearthfire home and craft all the materials yourself like hinges, nails and all that.

Daggers are still the fastest, in my experience.

Go hit up some Dwemer ruins and get some smithing materials. Make Dwarven Bows like crazy. Or make jewelry. I went from like 60 to 93 in just 4 or 5 days by doing that. And I wasn't even focusing on just smithing. I was doing other stuff too.

Make sure you bring a follower with you when you get the Dwemer stuff. Tell him/her to pick up the materials so you don't have to tote them around yourself.

Make weapons/armor/jewelry, then turn right back around and sell those. Buy more crafting materials with the money you made from selling the items you smithed.

Now, going from 95 to 100 is kinda annoying. I must've made 30 Dwarven bows and probably as many necklaces and rings and I only went up about half a level.

I have the dlc but never bothered how would one go about that?
Iron dagger right o.o?
Thanks I'll try that I suppose

Jewelry is very good especially if you have a pile of gems to make jeweled rings. These are expensive and raise smithing quicker. As a side benefit you can enchant them and sell them for even more to finance further smithing and enchanting.

dupe materials, like solid dwemer metal

That's what I'm doing. I'm grinding my enchanting skill but at the same time I'm grinding smithing and making coin.

For Hearthfire, just make sure you have tons and tons and tons of iron ingots. Iron has never been so valuable. To build a complete Hearthfire house you'd probably need more than 100 Iron ingots (or at least it certainly feels that way).

Lakeview in Falkreath is probably the easiest one to gain access to. Get the land, hoard up all that iron (with some corundrum - 20 or so - to build all the locks), buy lots of timber, mine up the stone and clay, and smith away. The wikis will probably give a better indication of how much materials you need.

Smithing gain is affected (I believe) by the "value" of the crafted item. Jewelry is how I have leveled fast.

It's incredibly easy if you plan ahead. I always mine all of the big ebony veins early on in the game so they can respawn later on for the final stretch (basically 80-100).

If you have the money just keep buying ebony ingots and ore (this is easier with the DLCs because they provide more smithing vendors) and make Ebony bows. Exploring the Dwemer ruins and collecting all of the metals will also make the process faster since getting ebony can be a bit of a wait. Just make Dwarven bows in between then and it should go much faster and be less costly.

Good luck.

I'm not sure about the "fastest" way but I believe the best way to level smithing is in conjunction with other skills. The problem with focusing on improving just a utility skill (smithing, enchanting or alchemy) is that it will cause your character to level quickly. This could cause problems with survive-ability particularly on higher difficulty settings.

My advice would be to go dungeon delving. Kill all the bandits or whatever loot everything then take it back to town, improve it with smithing and then sell it to the vendors. This provides levels in a combat skill of some kind, smithing and speech (even if you don't put points into the speech skill.)

I just now hit 100. Doing exactly what I said earlier. Buy smithing materials, smith stuff, sell those, buy more with the money you just made. Repeat.

Dwarven bows always dwarven bows. if you have 150 dwarven ingots/50 irons ingots, then make 50 bows and improve them all.

Though personally i create/temper a set of higher tier armor and weapons every then levels. That sometimes helps me get through the ranks due to how expensive the higher tiers are dwarven>nordic>orcish>ebony/stahlrim>daedric>dragon.

I keep a notepad that tells me when i last used up certain mines. That way i know when i can go back.