Position objects with your finger, or use the nudge controls in the rotation tray to move objects one pixel or ten pixels at a time. If you have a keyboard on your device, you can use the arrow keys to nudge one pixel, or Ctrl+Arrow to nudge ten pixels.
Use the Layer Manager to select objects within a complex design.
It is often difficult to select small or overlapping objects with your finger or even with a mouse. Use the layer manager to select and/or edit the desired object.