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@gbj_tester
There is a quick and accurate method; just clamp a straight edge to the chain ring and see if it hits the sprocket. If it doesn't, move the sprocket out a bit. If it presses on the sprocket, move the chain ring out a bit, etc.
Ideally, the straight edge should make a chord to the chain ring as large as possible without interfering with the chain ring bolts and spider, and of course you need to avoid the stays. As it turns out, a 1U 19" face plate is a pretty good tool for this job, the thicker the better as it makes it easier to clamp. A couple of small G-clamps are all you need to hold it in place. You may need to make compensating adjustments if the ring and sprocket thicknesses are not the same, e.g. Goldtec rings are cut from 4mm plate, so the tooth centreline is 2mm inboard of the outer face, not the 1/16" you would expect.