You can use smart guides to align the edge of the item you are moving to the edge of other items on the current layout. This is turned on by default for a new Layout window.
To turn on smart guides for a Layout window:
Smart guides display a visual cue (an orange vertical or horizontal guideline) when a Smart Guide is actively being used to snap items together.. The item automatically aligns (snaps) to the edge of nearby items as if there is a guide line. Smart guides include the border of an item, so that items visually align.
While using the left mouse to drag or resize an item, pressing and holding the Alt key temporarily disables all Snap to Grid and snap to guide behavior. Releasing the Alt key enables these behaviors.