On the control panel, click on one of the 3 rectangles according to the type of widget you want to draw.

The mouse cursor will then turn into a cross.

On the grid, click down on the point where you want to position the top left-hand corner of the widget.

Keeping the mouse button depressed, drag downwards and to the right.

When the rectangle of your widget reaches the dimensions you want, release the mouse button. The widget is now ready.

Of course, if you are drawing a picture widget, you do not yet know the size it should be. Draw the widget of any size you want. When you load the picture, it will be re-sized automatically. All widgets can be re-sized later on demand.