just wondering

I would say Cooking, because you don't have to worry about the fish/trees dying/moving away. You could do Fletching too.

Smithing works nicely too, if you smelt gold or something.

Combat can be to depending on the way you approach it.

Fletching?

I'd say making cballs, it takes 3 minutes to use up 26 steel bars, and it's pretty convenient to do it

cballs are slow as hell, perfect for afking

 

 

 

otherwise, use fire strike on the fire mage south of falador (or earth strike on earth mage). Those mages get healed when you attack them with "their" element, so they'll never die. Just wear black dhide and be prepared to die if you disconnect. Or, go to a place where there are weak monsters that attack you automatically (like Stronghold of Security) and wear guthans. 15 minutes of afk combat training, unless you get a random.

Combat. Every other skill requires attention after every inventory you complete. While combat only requires attention once every 5 minutes, which a brief glace (but no action) every minute to check on your health (if applicable).

Cannonballs, fishing (with sound effects ON), fletching (but only cutting the bows, not stringing).

Smithing Cannonballs

Fletching and Cooking... I'm even cooking at the moment as I post this :D

Fletching is rather convenient, as Iind making a full invo of unstrung bows takes like 30 sec-1 min.

You could always try smelting Iron Ores into Iron Bars with a RoF.

combat - monkey zombies

Grinding bones at ectofuntus / getting slime

Guthans at orks

Stringing Ammulets with Lunar Magic is great.

Cannonballs, for sure.

Cooking, Fletching, maybe Prayer with the Pray X thing, and farming of course (Combine farming with the other skills to get a better result :P)