pencil - takes too long and I get too detailed with pencil, I've also found that sometimes the lead mixes with my paint and makes a sort of grey mess
charcoal - same mess but some artists swear by it. I get messy enough with the paint, don't need any extra black sooty mess around me or the studio
enlargers - maybe, if I have the time to adjust it so that there's no distortion (which is easy to get when the enlarger is out of level) plus on this piece it's the spontaneity that's important, not the accuracy of details
Grid - nope, not on this one (see the commissioned portrait blog for details on that method) Besides, I'm ready to paint, not measure little squares.
So you see, there are lots of other ways I could approach this painting but I've chosen to just jump in and start. Therefore, here I go as I load a paint brush that is larger than I might normally use so that I won't get too tight on the drawing part. I usually use whatever is left on my palette OR a little light brown or yellow ochre paint. Looking carefully at the photo and it's placement of objects I use this observation as my first guidelines for showing me how tall the piece should be, where it should come in relation to the sides of the canvas and any outstanding features. The more the photo correlates to the painting (8 X 10 to a 16X20, rather than an 8 X 10 to a 11 X 14) the easier this is to do. I can see that the head comes about 1/3 over from the right side of the canvas, the guitar is at a 45 degree right in the center of the canvas, etc) These guideline points are marked in with quick lines or slashes of paint. Now I have the parameters of my piece.
In this painting my subject is a human. There are all sorts of schools, books, rules, etc for drawing the figure. For example the full figure of a normal person should be 7 - 8 heads tall. Once you draw an egg shaped area for the head, you can measure down 7 - 8 heads (refer to your photograph or model) and make a mark so that you will know where the feet need to go. Likewise you can "measure" this way to find out where the waist goes, the arms and the hips. From there the legs and knees and bends can be "measured" and figured.
OK, so you hate to measure. Trust Jane's Perspective on this - you'll measure now, when you can correct everything easier or you'll end up completing the painting only to find out that something just doesn't look right and you'll have to measure later to find out what to do about it. Do it now and save some grief later. And it doesn't have to be ruler type measuring. Just line up your paint brush with the height of the head on the photo. Slide your finger back to note the length of the head. Move that measurement to the body or the arms or the leg on the photo and see how it compares. Is the forearm the exact length of the head? Is the chest two heads tall? Is the knee to the foot one and one half heads tall?
Likewise, measure the head that you drew on your painting. Use the same proportions that you discovered on the photo to measure how long the forearm needs to be or how wide the shoulders need to be. If the forearm of the photo was the same length as the head on the photo, you make the forearm of the painting as long as the length of the head in the painting. Get it? Make tiny slash marks for the proper lengths or widths or anything you want to measure and all you will have to do is fill in the blanks between these marks.
Here's another hint I use to create my figures. I draw stick people. Yep, good old stick folks so that once I start measuring I can just draw right over or rearrange body parts as necessary.
You can sorta see the stick figure in this painting and you can see how the parts relate to each other. I add more details as I get the parts in the right spaces. 
In this picture you can see how I change my sketch as I go along. Normally I just use one neutral color like a yellow ochre to draw my picture but in this demo I switched to a darker brown so that you can see the corrections I make as I go along.Up close you can see how much the leg moved. As I created the body I start not only measuring but relating one part to another. When I drew an imaginary line straight down from the shoulder I saw that the foot should have been directly below. I had it too far to the left so I moved it in the sketch. Imagine how much trouble this would have been had I painted the whole painting and then tried to move the whole leg over.
You can get as detailed as you want with this initial sketch and if you find mistakes you can easily cover them with paint later in this project. Plus because this project is so spontaneous with the colors, some of these "mistakes" make turn out to be happy accidents. Look how, in this sketch, the leg seems to have motion.
Likewise on the hip, as the guitar came into play I saw where the hip needed to come over to the right more. Again an easy fix at this point.
Like I said, you can take all day and draw details til the cows come home but aren't you ready to paint yet? I am. So here I go with one of the most unusual underpaintings that you will ever see.
Likewise on the hip, as the guitar came into play I saw where the hip needed to come over to the right more. Again an easy fix at this point.
Like I said, you can take all day and draw details til the cows come home but aren't you ready to paint yet? I am. So here I go with one of the most unusual underpaintings that you will ever see.