On Mon, 9 Feb 2009 22:30:23 -0800 (PST), wrote:

I just put up white crown molding. I used angled (45 degree) scarf
joints where two pieces meet along a wall. I matched the joints very
carefully but slight differences in the elevation of the two sides
seem magnified. I've tried caulk, wood filler, and lots of paint, but
the joints still seem visible. Is there a trick I am missing?

Thanks,
Tim

Lots of tricks. A lower angle would be better than a 45-degree angle.
Fit the two pieces on a workbench, glue up, reinforce the back with a
thin stock, and allow to dry overnight. Using various dowels and
other objects sand the joint perfectly smooth, carefully inspect,
prime, paint. You could use a biscuit which will make the alignment
easier.