A lot depends on what you want your main focus for your tradeskills to be. Do you want to make gold, or do you want to create things for yourself to use? The two goals are mutually exclusive.
Production skills don't make money unless you can find a niche (and niches usually come only at high levels of the tradeskill). Not only that, but production skills will use up the materials you gather with your gathering skill, so you end up not making any gold by selling mats. Production skills, however, can produce items that you can use for yourself.
Gathering skills will get you gold, but won't make you any potions, armor, weapons, or enchantements. On the other hand, they will get you enough gold to buy those.