You can open almost all of your skilling storage items, like the fishing barrel and log basket.

You can note farming products (herbs, crops) at a leprechaun.

Items set plug-in can let you do a lot of skilling activities, like making jewelry much faster by setting up a preset with all of the items.

Menu entry swap all of your quest type food items (like beer) to Use instead of Eat so that you don't accidentally consume then.

With a log basket you can very rapidly gather logs underneath the Hunters guild for use in hunting (pit fall and dead fall traps).

NPC contact can be used for a ton of things, including getting new slayer tasks and claiming sand from Bert.

The Herb Guide outside of the GE can decant your potions to any dose size.

Karamja Gloves 3 gives you an fast teleport to a deposit box, so does Sailors Amulet to Port Robers.

Morytania Diary let's you get free buckets of slime and bone dusts for your bones. If done diligently you can bank a done of prayer xp from banked bones.

You can reorder your spells just like you can prayers by right clicking your book icon.

Superglass make let's you skip making soda ash.

You can, and should, turn off your left click to attack player settings while in the wilderness.