Dragon Age - If I make a new character for awakening can I go back and play origins with that character?

When I was a noob I made a warrior and focused on sword and shield, which completely restricts use of warrior companions. I'd like to be a mage in awakening, but then I'd want to get that mage more xp in origins.Dragon Age - If I make a new character for awakening can I go back and play origins with that character?
You wouldn't be able to go back on Origins and play this character.

The whole point in Awakening is to carry on from your Origins story.

(:Dragon Age - If I make a new character for awakening can I go back and play origins with that character?
No.



Awakening occurs AFTER Origins in the timeline.



In Awakening the blight is over, and a new King/Queen rules Ferelden. In fact, YOU are not from Ferelden, since Alistair and the PC were the last Ferelden wardens. You start as an Orlesian warden arrived after the blight.



In Origins the blight has just begun, there are only two Grey Wardens, you and Alistair. Your actions will determine if he becomes King, or dies, or not. You might even survive the final battle yourself and go on to play the only full-time Fereden grey warden in Awakenings until you recruit more.Dragon Age - If I make a new character for awakening can I go back and play origins with that character?
You would have to go back and create your character in Origins, can't take a character from Awakening and go to Origins, since Awakening is further down the time line from Origins.

Edit: You can use the character from Origins in Awakening as long as he/she survived the blight.
I'm not really sure what your question is. Do you want a character to have a lot of experience points (levels)? Is that why you want to switch them back after playing Awakening? If THIS is your question, then that's rather simple. You don't need to worry about experience. There are a few tricks (not really exploits) you can take advantage of in Origins that will help you level fast (and can make you money too!). (SPOILERS BEWARE)
Trick 1: The first one only requires that you have 1 character with the trap skill. When you are in Lothering, before finishing one of the main quests, talk to Allison who is located near the bridge just west of the Tavern. She gives you a trap quest. You need to buy 3 trap triggers (7.8 silver cost total) and she will reward you with 100 experience (as well as 50 silver) for doing the quest. If you talk to her again, she will thank you for helping her with traps. If you talk to her yet again, then you can get that quest over, and from here on you can keep bringing her traps to turn in for experience. This ONLY works before Lothering is destroyed by darkspawn. If your question is more about how to get your mage experience, this is the way to go. I've left Lothering with characters at level 20 and haven't even begun playing the game XD. Be forewarned, doing this makes the game a lot harder, too, as the creatures also level with the character.
On a side note, doing this quest enough will get you cash to buy some of the runes, books, and other items the camp merchant sells. Once you leave the camp the first time, his inventory resets--so if you bought those rare books from him the first time, they will be once again made available.
Trick 2: Get one of your mages (Morrigan is probably the easiest) to level 4 herbalism and make tons of potent lyrium potions and sell for a profit, then donate 30 gold at a time to the allied supply crates for the Redcliffe soldiers in camp after you finish the Arl of Redcliffe quest.
As far as reverting characters, you are unable to revert characters in Awakening back to Origins.