Soaking the rice and dal is optional but recommended to shorten the cooking time. If you don't soak, then keep the kichari on low flame for an additional 10 minutes.
The proportion of rice to dal need not be half. There are times when we add more lentil to rice, since that tastes better, even though my personal preference is half-half.
The liquid to rice-dal ratio is slightly higher than double. The lentils tend to soak up a lot of water and can leave the kichari dry, so adding a little extra water will not do any harm.
Serve it hot. Keeping it to room temperature tends to harden it. To loosen up the mixture, add hot water and mix till the consistency is reached.
You can use only milk or coconut milk, instead of both together. At times I run out of both, I add equivalent amount of water and mix in coconut milk powder or milk powder (4-6 heaped tbsps approximately, in total and whisk well, before adding.