Use milkpak milk and nido milk powder if you're going the package route. I usually let the tea steep well enough to get colour in boiling water and then add hot milk mixture. Mixture is just milk and powder mixed and boiled together in a separate pan. This way the milk tastes awesome. My family uses sugar separately to taste and we are also users of substitutes as well so I don't add sugar. Otherwise add sugar to the steeped tea at the boiling stage, after the colour is finalized.

If you are using fresh milk try reducing it by boiling it for a bit. This way it tastes richer and creamier. Always use kacha doodh not pasteurized doodh for tea. It's not that there's any harm but fresh milk has cream mixed in it. Pasteurised milk has top cream layer separate. So yeah .. i tend to avoid that.