I just started with a new build and i was wondering, what or when would be the best time to do the DLC maps/missions?

I know they give good Xp and usually you get some good weapons or apparel from doing the DLC's, but when would be a good time to do them? Is doing them early in the game a good strategy...or would it be better to do them when you character is stronger and you have better weapons?

Gime you're 2 cents on this matter, i do greatly would approve of your expertise.

Thanks.

Ronny