Rick,
This is where Snap Markers come in handy.
Say you place a door and when you highlight it you can tell that the right side is 143\" from the right wall.
You want to set the cabinet 3\" from the casing so you place a snap marker where your cabinet will hit it and then highlight the snap marker and use the numerical entry box to set the marker 140\" from the right wall.
With the insert item method set to align to back place the cabinet and bump it to the snap marker.
Your cabinet is now 3\" in from the door casing.
Snap markers are good for placing things exactly. They have no length or width so wherever you place them is where your cabinet will be when you bump it.
I forgot to mention that you can use formulas in the entry boxes so that you don't have to think. You can put something like 143-3 to get your spacing. This is good when there are fractions 143-2 15/16
You can also use complex formulas using parenthesis IE (2 3/16)*(1 1/2)
This is a fantastic way to align items on walls. For example. Insert a range hood; enter zero in the left or right field box and press enter, multiply the opposite value by .5 and press enter. If that value has fractions, just place a set of parrenthesis around them. (108 1/32)*.5 and press enter.
One note about elevation view alighnment using these boxes. They don't seem to work well if the cabinet is associated to a angular wall. Unassociate that cabinet and it should work fine...
My personal opinion on this is; that the software is trying to move the cabinet along the angled wall it is associated to. This does not happen all the time. But when it does, you know what to do to eliminate the problem.