Didja hear the one about the patient of the doctor that bumped into the sawbones at the grocery store?
Patient: Hey, doc! Whadya think I should do about this new pain I got? I got fever, chills, and some new shoes last month, but I'm heading off to vacation
next week and don't have time to make an appointment with you in the office!
Doc: Kinda hard to tell you what's wrong when I don't have a chance to examine you and run some tests.
Do ya think ya could point us to at least one example of your poor flash shot so we could have an idea of what you're talking about?
If not.. make sure (a) you're setting your camera to MANUAL, not automatic-anything (b) shutter speed to about 1/125 or so (to make sure your camera is slow enough to synch with the strobes), and adjust your aperture (start out at ISO 200 or so before jacking it up to 3200 or 6400) until you get a well exposed image (do you know how to read the histogram on the D70??).
A flash meter is definitely valuable when you're using studio strobes that don't meter through the iTTL system of the D70 - $250-300 (depending on where you buy it) or so should get you a perfectly good Sekonic L-358 flash meter. There are flash meters that are more expensive out there - there are flash meters that are less expensive. There aren't any meters out there that are more recommended by many of us.
So, Joe.. help us help you out, here, ok?
Just some eye candy, because it's appropriate for this thread....