Too loose.

I had a front wheel give me all sorts of commotion when I'd really mash, and it was one of my first sets of handbuilt wheels, so I wasn't sure about what was good tension.

The LBS spent a good 10 minutes walking around the rim and pulling more tension into it, and it stopped the creaks and made my bike feel like I added 10psi in the front tire. You can also put some light oil at the crosses and at the nipples.