You need to get someone sitting down first, which could involve going to a special class for artistic enjoyment or there are classes where there are volunteers who are paid to be life models. You need not worry and start off your pencil or chalk at the head and work down until the hips. You have to take into account that the body is not a perfect shape and comes in all shapes and sizes therefore you need to trust your creativity and be imaginative.
Once you have drawn your head slightly to the right you can work your pencil or chalk down to the arm area and to the inside of the armpit and arm so you know where you are aiming for. Then it is down the elbow then down to the waist.
You then need to focus on the hip area where it is now time to draw the torso and you just need to work your tools along the natural lines of your subject. You can also try and do something called foreshortening involving both interweaving long and short lines but you should ask your instructor for more detail on how to use this technique.
You can also do a lot of practise before you even decide to go to an art class. You need to keep using your pencil or chalk to measure the distance of your object. Simply go online and download a photo or even get it enlarged. Once you have a large photo of a subject sitting down you can begin to use different strokes in order to obtain a more accurate drawing. You have to take into account what you can see as opposed to what you cannot view in the perspective.
Once you have drawn your head slightly to the right you can work your pencil or chalk down to the arm area and to the inside of the armpit and arm so you know where you are aiming for. Then it is down the elbow then down to the waist.
You then need to focus on the hip area where it is now time to draw the torso and you just need to work your tools along the natural lines of your subject. You can also try and do something called foreshortening involving both interweaving long and short lines but you should ask your instructor for more detail on how to use this technique.
You can also do a lot of practise before you even decide to go to an art class. You need to keep using your pencil or chalk to measure the distance of your object. Simply go online and download a photo or even get it enlarged. Once you have a large photo of a subject sitting down you can begin to use different strokes in order to obtain a more accurate drawing. You have to take into account what you can see as opposed to what you cannot view in the perspective.