Tricky at first, but seriously useful when you need precision for a still life, portrait, or complex landscape.
The first illustration here is a bit misleading, because in my version of sight drawing, you will also have a second pencil (or a brush handle, or twig, or even a flat strip of wc paper) in your NON-dominant hand -- this is what you will use to MEASURE the objects.

For now, we'll assume for clarity's sake that you are holding the end of a long BRUSH in your LEFT or  Non-Dominant hand, for measuring.
 Your drawing PENCIL is in your Dominant RIGHT hand.

Hold your LEFT arm straight out and be sure your elbow is straight and locked. If you bend your elbow (easy to do without thinking), you change the scale of the measurements. If your elbow is locked, your measurements stay constant because your arm doesn’t change length. Therefore, you won't inadvertently distort the distances you are measuring.

You must also remember not to lean forward or back, whether sitting or standing; this too will distort measurements. Memorize your posture and keep it.

Finally, be careful that your brush handle is parallel to you. If it's at an angle, it throws off the measurements.  

Now, close one eye, lock your elbow, and measure: The tip of the brush handle should be even with the top of the object (in this case, her head). Then slide your thumb down until it is even with the bottom of the object, ie the chin. Best to hold the brush OVER the object if possible.

At this point, you can bring your left hand to the paper, and make marks with your right hand to transfer this measurement to your paper. Yes, this is super tedious at first...

However, WHERE to make those marks? it's much better to start by drawing your border on your paper, as we did in Week 1. Where will your still life be situated? You have to have SOME idea of this before you begin.

Below, the focal point (wine bottle) is slightly to the right and follows the Rule of Thirds. Continue reading to learn how to place each object correctly in relation to the others and to the paper's edges.

A simple still life set-up that you want to draw.  
Check your COMPOSITION: This is good (if slightly boring), and obeys the Rule of Thirds. You're always looking for interesting asymmetry.

Best to consider this and rearrange onjects BEFORE you start sight drawing!
[1]  In Sight Drawing, you first measure the overall "box" that contains the main objects/elements in your image --
the N S E W points.

Here, North is the top of the bottle,
South is the bottom of glass,
East is the right grape edge, and
West is the left apple edge.

NOTE: you may need to move yourself, or the still life, closer or farther away in order to get the right size drawing for your paper.

Of course you need to consider where this box best appears on your paper. Here's, it's a little to the right of center.

Remember, your focal point is ALWAYS off-center, so you want to be sure, in this case, that the wine bottle is on a one-third line.
[2]  Then you measure the correct size and placement of smaller "boxes" that contains each main element in your image: Bottle, wineglass, fruit, etc.
[3]  Here is the correct size a "box" that contains the wine bottle. Note the glass overlaps it.

Later, further measurements allow you to place the bottle exactly where it belongs in relation to glass, fruit, etc.
[4]  Sometimes the elements overlap one another. This "box" contains ALL the fruit...

 you could make smaller boxes for just the apples, or even for EACH apple, if that's important to you. The wineglass already has its own box.
[5]   Where to place those grapes? First  measure how far from the right edge and bottom edge the “Grape Box” should be -- see #6 following.
Then you can measure the correct size box for these
Of course this is simple enough that you can just
eyeball it as well.

[5A]  Here are two of the overlapping boxes for the four main elements.

Note you could even make further measured boxes for the handles on the wine bottle...again, only if that needs to be precise.
sight dwg 5a
[6] Measuring NEGATIVE SPACE:

Measuring the OBJECTS is easy, but correct placement means you must often measure the space BETWEEN the objects. Ditto the space between the object and the edge of the "box" in which they are contained.   

That is, depending on the level of precision you need, you begin by measuring the "invisible" line between A-B, and transferring it to the paper.

Now you know where the left edge of the bottle should be. Measure B-C for the bottle, and draw vertical lines through those points; now you have the sides of the bottle. Then measure C-D, for the right edge of the box.

The top is the North point; the base can be estimated, or measured if you like. It falls a bit above the glass base.

Measuring E-F tells you where the top of the fruit should be. The area BELOW the fruit is very small, so you need not necessarily measure it.

The wineglass is actually almost perfectly centered, between the M-N distance and the O-P distance. But in the finished drawing
[7]  It's up to you whether EXACT placement is important. For example, the fruit could be drawn with less precision.
Or rearranged, or added to, etc.
Review:  In Sight Drawing, you first measure the rectangular "box" that contains ALL the important  objects/elements in your image -- the N S E W points.

North is the top of the bottle,
South is the bottom of glass, etc.

Start from one side (usually the left side, if you're right-handed), and measure your way over to the other, making marks and drawing verticals and horizontals as you go, to create the boxes.  

Keep that elbow locked! One eye closed.

Of course, you can also rearrange, eliminate, or add elements if you like...especially if you're outdoors drawing a landscape.

Once you have these boxes, it's far easier to draw the objects correctly, especially symmetrical objects.

Yes, this is super tedious at first.

But once you've done it a few've trained your brain to think in different terms, and the day will soon come when you don't have to be so exacting! You'll develop a much better sense of how to place the 'boxes' to create a correct drawing...without so much measuring.



Here's another still life for practice. You can print iit out (full sheet of printer paper if possible) and draw a box around the entire arrangement; then around the various important elements.

Note that here, the ellipse that is the opening of the bowl is small and narrow...but is actually very important for correct perspective. This is where sight drawing comes in really handy. Shapes like this are so easy to misjudge. If you get them wrong, the whole drawing looks off.

So the entire bowl might be one box, but the opening and/or outer lip might be another box...or even two.

In a landscape, Sight Drawing will help you correctly place a curved  road, river, or shoreline.

Extra credit:
Set up your own simple still life and use Sight Drawing to draw it.
Extra extra credit: put an angled place mat beneath the objects and use your "clock time" knowledge of angles to draw that too. Then send me a pic of both!