Getting your children to properly hold a pencil need not be something stressful or worrisome. The answer is "learning through play", one of the key beliefs on which the Montessori Approach is based.
There are a number of fun, inexpensive activities that most children might consider just a part of playtime but are actually valuable pre-writing exercises that strengthen the "3-finger-grasp" and prepare them for writing.
One such play activity involves the use of the clothes pins or "sipit" in your "sampayan". Give the children a couple of sipits to play with. They could attach the pieces to each other to make a robot, a plane or a pretend person. Observe how they hold it. Yes, they use the three fingers to clip and unclip the sipit, a pre-writing exercise.
Empty perfume or cologne bottles can also be used to exercise the children's hands. So that there is order in the activity, the children can set the bottles in a row on the desk. They open the bottles one at a time and then put the caps back on.
A pack of red beans, mung beans or rice grains, a spoon and 2 bowls will also be very useful. The children use the spoon to transfer the beans or grains from one bowl to the other. Again, observe that holding the spoon involves the 3-finger-grasp. When doing this activity, you can set the bowls on a tray to catch the stray bean or grain.
Small tongs to transfer cotton balls from one container to another is also a good pre-writing exercise.
Have fun with your kids!