Hi PP - if you want to position objects so that they snap on to each other (like matching a corner to a corner or things like that), you need to enable the "Object Snap" snap option.

In your video things are more difficult than they need to be, because you do not have Object Snap enabled.

To enable it, click on this button here in the bottom toolbar:



When that is enabled (it will be highlighted in orange when turned on), when you drag an object somewhere close to a snap point it will grab directly on to the snap point and help you to accurately position the object. You just have to grab on to it somewhere nearby the point of interest, you don't have to be quite so precise as in your video. You can also adjust the snap radius under Options > Snaps > Object snap options > "Snap radius", if you want to increase the radius in pixels around the mouse location that will be searched for a snap point to lock on to.

And also as others mentioned above you can hold down the Ctrl key to drag off a copy of an object which is convenient to use in cases like this.

So for example with Object snap enabled and with holding down the Ctrl key, you can do the type of thing that you are showing there way more easily, it looks like this:



So again the key thing there is that Object snap is enabled, and I'm holding down the Ctrl key to make copies while dragging.

Also notice how there are some little tags showing up like "End", "Mid", and "Cen" - those show up when you have object snap enabled and they tell you which kind of snap is currently engaged. When you are dragging an object before locking it on to another one of those tags will also show up on the point on the object that is being positioned.

Usually when you are drawing you will want to have both "Straight Snap" as well as "Object Snap" enabled to help you with these kinds of tasks.

Straight snap helps lock things onto the x, y, or z axis directions when drawing lines or also when dragging objects.

Grid snap is for locking points on to the grid points only - usually if you want to position objects that are relative to other geometry you will want to use Object Snap for that and not grid snap, grid snap can help you to create the starting object and then turn it off once you want to only work on snapping things to existing geometry after that.

So for normal work, have grid snap disabled, and straight snap and object snap enabled - turn on grid snap for a while when you need it for a particular drawing and then turn it back off again once you are done with it.

You can also hold down the Alt key to temporarily disable snaps just for a single pick.

Hope this explanation helps!

- Michael