1)Always use full fat milk for making chenna.
2)Adding lemon juice to curdle the milk gives a nice flavour to the chenna.
3)You can reserve the whey water in a air tight bottle and when you make chenna for the next time, add this instead of lemon juice.
4) You have to wash the chenna really well to get the extra sour taste.
5) Hang the chenna to remove excess water, never place weight over it , it will make them tough.
6)Dont add too much sugar to the sandesh, else it will leave so much water.
7)Don't over cook it, else it will turn crumbly. Even if it turn crumbly or looks a bit dry, take it in a blender and puree till smooth, so you can shape it into ball.