Even with a tool such as the 3D Cursor that helps with alignment, you still can get another great option to place objects using reference points such as vertices, edges, and faces.
In the Blender user interface, you will find a small magnet icon at the bottom of your 3D View window, which will activate the snap during a transformation action. Once you enable the tool, all transformations will start to look for reference points.
For instance, when you move objects, Blender will start to look for vertices that are close to each other. Once it finds a vertex that matches your criteria, Blender will place them together.
Where is this tool? You will find it at the bottom of the 3D View window as a small magnet icon, as indicated in the following screenshot. You can also enable and disable the tool with the Shift + Tab keys. Click at the button right next to the magnet to set the options for snapping:
You have to choose a snapping element and then a target. The element will set what Blender will look to position an object. The options are increment (grid lines), vertex, edge, face, and volume (whole object). For the target, you have to choose what parameter Blender must use to track both objects. As targets for snap, you can pick closest, center, median, and active.
For instance, you can set the snapping to vertex and target to closest, and by selecting and moving the chair, it will quickly snap to the wall.
To achieve that, you have first to select the chair and activate the snap. Choose the proper element and target. Place the mouse cursor near the location you wish to snap to and press the G key, as shown in the following screenshot:
Now, move the mouse until you reach a corner of the wall. A small circle will appear near the vertex that Blender will capture as the closest vertex to the object. If you click there, your model will stay at that location using only the mouse, as shown in the following screenshot:
With the snap during transform, you can have full control over locations using only the mouse.
Another great feature of that tool is the Align Rotation option, which can spin and align your objects with non orthogonal surfaces, as shown in the following screenshot:
