Must not do -

Do not
enact at the drop of hat.

Govern continuously not by interference but by being a facilitator.
Keep the number of laws minimum and implementation of law foolproof and strictest .
Decide the shape , size and sharpness of your law, educate all stakeholders really threadbare but get the compliance 100%.

Do not
allow disobedience.

Don't
punish human body , it develops immunity. Punish wealth in all form . Wrong dowers must suffer more compensatingly than savagely or inhumanely.

Do not
allow a single person to enjoy a single penny he has not earned rightly.