Did some solo, some WT world, 99 got me roughly 61 construction and fletching. (69 is expected with pure solo)
Construction is the only one you really want levels for, minimum 15. Just remember your levels don't matter when acquiring the crate, only when you open it.
Herblore and farming xp doesn't exist. If you run and made potions all day in WT, you'd see how it's so bad.