Objects appearing in random place on z axis - help! (setting starting coordinates)

Hi guys,

This must be a newbie question - and I'm hoping there's a super easy answer to this that I'm not seeing - but I have a project with a lot of 3D aspects and I'm slowly being driven CRAZY...

Every time I create a new object - rectangle, bezier, whatever - it creates it by default at what seems like an arbitrary Z point (I can't figure out how the point relates to anything else in the project), usually far back in the distance, so I'll be drawing something at what seems like my intended scale but it's really far away and when I move it to the desired Z point it's obviously huge or off screen somewhere. I'm creating lots of things, doing lots of camera movements etc, so creating things then putting them in their proper place & scale is QUICKLY becoming a real drag on this project.

Any way to set the starting coordinates (at least Z axis)?

Any tips would be a huge help!
Thanks