according to one's own lights

according to one’s own lights (according to the way one believes; according to the way one’s conscience or inclinations lead one. (Rarely used informally.) — в меру своих способностей (возможностей); в соответствии со своими убеждениями; в меру своего разумения; в меру своего понимания; ~~ судить в меру своей испорченности (контекст.)

Example 1: People must act on this matter according to their own lights.

Example 2: John may have been wrong, but he did what he did according to his own lights.

[do as you think best]
[suit yourself]
[do as you see fit]
[whatever floats your boat]
[at will]
Have it your way;
As you wish

it's up to you to decide