I've only gotten my priest to 60.
I've several lower level alts in other classes (38, 29,26, 22, 26, 16)
Have tried all professions other than jewel crafting.
I strongly recommend two of the three gathering professions (skinning, minig, herbalism) to at least level 60.
If you don't mind not getting a mount and usually being broke, try anything.
I have decided skinning and herbalism makes the most sense. I don't.
I have done mining and herbalism. It is a lot harder to level up mining.
300 at herbalism at 53, 284 mining at 60.
Have an auction house alt (or two--I've two accounts so I have alts to buy and sell from alliance to horde and vice versa)
You will be able to buy a mount or two, good gear and have at bit of money left over if you do this.
If you craft early on--it's much harder.
Want gear? AH or trade channel. Many professionals offer services for a reasonable cost on my server (Eonar).
Only alchemists aren't out peddling. AH treats them well for specific potions and elixirs.
You can repect at endgame for any specific items you may want later.
Thsi seems similar to the other posters, who have watched mistakes or weem what may or not work well through the game.
All the best
Good gaming, Be well.