Tips
Holding down the Shift key while using the Move tool will let you make small vertical adjustments [UP & DOWN] to the position of a furniture item.
Holding down the Ctrl key while using the Move tool will let you make small horizontal adjustments [Left & Right] to the position of a furniture item.

Access the locking feature by selecting the padlock icon then clicking on the furniture item you wish to lock. This will lock the furniture item in its place. Locked furniture cannot be edited.
To unlock furniture reselect the padlock icon then click on the previously locked furniture item again. The unlocked furniture item can now be edited once again.

Offsetting: Attachment points, or Nodes, are located on the floor of your room and allow you to attach pieces of furniture at those locations. But if you want to place an item where there are no nodes, you will need to offset the item. For instance, if you want to place a plant on top of a table, you will need to offset the plant from its attachment point. To do this, attach the plant to a Node on the floor underneath the table. Select the Move tool from the furniture editing menu at the bottom of your screen CTRL+D (make sure you select the DECORATE TOOLS BUTTON to enter Edit mode or the Edit menu will not be visible)

To move an item vertically, use Move+Shift CLICK & drag; to move it horizontally, use Move+Ctrl CLICK drag. With the Move tool selected, hold down the shift key and drag your plant up until its base is level with the table surface. To move the plant to one end of the table, use Move-ctrl-drag to move it sideways. Try rotating around the plant with your camera until you get the sideways motion you want. Note: The latest versions of the IMVI Client no longer have a maximum offset distance.

Recap: Move-shift-drag offsets vertically, Move-ctrl-drag offsets sideways.