I am going to give you the basics and with some practice you can do some amazing drawings.
Below is an image one of my middle school students did of me.
Step 1: Getting Started
Here is what you will need:
Picture or printed image. (For this we will use an 8"x10" printed image)
Big piece of paper (for this it's 18"x24")
Straight edge (long ruler or stick or yard stick)
Start by gridding you 8"x10" image.
1. Starting in the corner of the image and moving across the top, side, bottom and other side make a mark every 1".
2. Your marks on the top and bottom of the image should line up. Same with the sides
Step 2: Drawing the Grid
Do the same thing from side to side.
This will create a 1" grid over your image
Step 3: Letters and Numbers
And numbers down the side.
Note: that "1" & "A" are the same square!
Step 4: Grid the Big Paper...
On your big piece of paper, starting in the corner, make a mark every 2" across the top, down the side, across the bottom and up the last side.
Using the straight edge, stick or yard stick to connect the makrs from the top and bottom.
Connect the marks from the sides with the ruler.
All your lines should be parallel.
*(It's the same as the little paper.... your just doing 2" grid rather than 1" grid)
ABC's & 123's... Across the top of your big paper put a letter in each box...
Down the side put a number in each box. "1" & "A" are in the same box.
When you are done you will have a big paper with a 2" grid.
Step 5: One Square at a Time...
Now you are going to draw one square at a time.. that's the trick. Anyone can do this and it turns out really cool.
Start in square 1A.. whatever is in that square draw it in square 1A on the big paper...
Then move to square 1B... 1C... one square at a time.
The trick is to draw in the big square... whatever is in the same little square... one at a time.
I am currently working on this drawing and will post the images when I am done.
*(I have included some presentations that I have made that might help)