Up to you really. Once you start buying bag upgrades and horse saddlebag upgrades you shouldn't have too many inventory issues - I've comfortably done Blacksmithing, Woodworking and Clothier on one character (only using 1 set of motifs that way) and Provisioning and Enchanting on another.

If you're planning on leveling two characters concurrently though definitely do it on a second character as long as you're willing to transfer materials. I'm not sure if they changed it since about a year ago but I had Provisioning maxed by just level 20! I think back then the perks that increased the amount of food/drink you make per batch actually multiplied your experience as well.

Yeah I was thinking one character would be a heavy armor dragonknight who focuses on enhancing and blacksmithing. And I was thinking my other character would be a light armor "cleric" type build using using the Templar skills and a staff, and maybe focus on alchemy and something else. Do you think that would work?

Having two characters on the go seems pretty weird, normally in a TES game I have tunnel vision until the character concept I'm exploring has reached a satisfactory conclusion. Yet in ESO having two characters may be an ideal way of maintaining sanity. I just hit level 17 and, after all that time waving my glowing spear around, I do feel the need to mix things up a bit.

I think that has a lot to do with seeing everyone else run their builds, or at least it is with me. As soon as I see something interesting I'm already planning a new character in my head. 

I'm not really a mechanics oriented sort of guy so I'm pretty slow picking up on that stuff. I'm more inclined to be inspired by a roleplay concept or an aesthetic. At the moment even though I'm having fun with my character, I'm finding I'm missing certain things. I keep getting staves, robes and other pretty useless stuff as rewards and it's making me want to try out a sorcerer. Plus, I'm very curious about Queen Ayrenn and need a break from all the knights and castles the DC are throwing my way.

I haven't seen a Khajiit or Altmer in about 15 hours.

Dude, come hang out on Stros M'kai! We have Khajiit, Altmer and even pacifist Orcs over here.

I enjoyed Stros M'kai, very vibrant. Those bight colours and interesting architecture are things I'm missing as I wander Stormhaven. It's beautiful in it's own way but always familiar. I'm going to roll an Altmer for a change of pace before diving back into knights and castles in a landscape and climate very similar to my native Britain.

Yeah after running around Stros M'kai and looking at the stuff to come in Craglorn it really makes me want to try a Redguard mage, all that Magna-Ge\Celestial and Redguard lore! But I kinda don't want to use another character to run through the Daggerfall stuff again. I might do it with a Khajiit instead.

Definitely, though like I said doing all the gear crafting skills on one character saves on motifs. Some of the rare motifs are quite valuable - Imperial was going for about 40k gold last I checked, and the Dwemer pages cost ~10k gold each unless you farm them yourself! Don't want to have to be buying (or farming) multiple copies for different characters I don't think.