How can I tone different parts of my body

You could begin your exercise routine with a few basic stretches to warm up.  These will help to relieve tension and warm up muscles and joints, preparing your body for slightly more intensive exercise.  These stretches will also stimulate blood circulation, and send the foetus a good supply of oxygen. 

Head and Neck:
Tilt your head to one side, then gently rotate your head to the back and then to the other side.  Complete circling your neck by bringing your head to the front, with your chin touching the center of your collarbones.  Repeat this exercise about 5 times in one direction, and 5 times in the other direction. 

Waist:
Sit on the floor and cross your legs. Gently stretch your neck upwards keeping your back straight.  Turn your torso to the right while breathing out and place your right hand behind you for support.  Your left hand is on your right knee while you stretch little further. Hold this position for a few seconds and repeat it upto five times in one direction and upto five times in the other direction.

Arms and Shoulders:
Sit with your legs tucked underneath your thighs, lift your right arm up towards the ceiling. Now bend the elbow and drop your head backwards. Hold your right elbow with your left hand and stretch a little further.  Next, put your left hand down and stretch it behind your back to reach out for your right hand.  Stretch for about 20 seconds and then relax. Repeat with the other arm.

Legs and Feet:
Stretch your legs out in front of you and keep your back straight. Place your hands on each side of your hips for support.  Gently bend your knee and straighten.  Repeat with the second leg. (This will help tone your muscles and relieve cramps) Flex your foot outwards and draw circles in the air with your ankles. Do not strain.