This was my first attempt at Intarsia. I would not recommend that newbies try plaid. I almost burned the needles, threw the yarn out the window and killed myself. But it turned out really well and was definitely a learning experience. Next time I'll cheat and do the tiny vertical stripes when it is done!
Here is the link to the general chihuahua sweater pattern I started with. The plaid I made up, and I have since changed the general pattern many times. I just make it up as I go now!