first, install a boost gauge, about $15 from any auto parts store that carries stuff like neon lights and honda fartcans.
I had bought one off ebay too, it its lowest setting it was giving me 15psi, way too much. it would have eventually started leaking oil out too if i had left it on there.
for a make it yourself controller, take a larger piece of hose about 2 inches long, wrap it around your wastegate line, and attach it with a hose clamp in the middle, tighten the clamp to raise boost, a small turn makes a big difference!
You can see mine in this pic:
